Curious if NaturDao, even more than 1 pill are enough to withstand the brute force of an aged beef stake.

Hello,

I’m extremely sensitive even on low bucket after my most recent infections, set back with ilnesses and necessary IV antibtiocs for GI infections.

Unfortunately, I can’t use an instapot right now for issues with our electric.

I’m down to just potatoes I can tolerate and need to expand that.

what’s the lowest histamine way to cook chicken and meat? Should I boil it? How so? Or should I put it in the oven? What works for everyone whose extremely sensitive

I can’t continue to deal with these severe migraines and severe system wide issues

Please don’t recommend mast cell stabilizers I have tried and have many conflicts or severe reactions.

Have tried DAO and many supplements as well

I understand there is not a lot of data but it's low risk to try. Did Singulair work for you?

EDIT something occured to me that might make it more immediately obvious what happened and why i just experienced two nights of high anxiety insomnia:

Just like when i had the incident with the ham (cured meats) where i suffered similar anxiety and symptoms, after some thinking it occured to me that I actually ate something out of the ordinary the day before the symptoms started up.

I had two regular potatoes (skins on) I baked in the oven. I never eat potatoes, because i had been keeping out nightshades as it was my initial suspicion maybe a year or more ago.

I stayed so focused on the histamine as of late, that i called into question if i really had the nightshade sensitivity, as the nightshades i was reacting to (paprika, tomatoes) were also to be avoided because of high histamine.

Google AI Mode summary suggested that the chemicals in the foods that can cause these reactions can stay in the body for several days. This could explain why I only started to become symptomatic the day after.

I was pinning the blame on the water broth i made with vegetables and the lemon (because the lemon is citrus), which ultimately confused me and maybe didn't even add up that much because the night even before the meal with the potatoes I made a meal with salmon with the same broth to zero symptoms.

So right now thats what i believe - that this was a strong and delayed reaction to the two whole potatoes I ate which are nightshades, which I've avoided for months if not over a year.

---

Really looking for some direction here, assumed histamine intolerance.

Guys, I’m really sorry how discombobulated this all is.  I’m just so tired and this has been getting bad - after a decade of this I’m just getting tired.

Hey everybody (I’m 35, male), I’m not really sure what to do here or what to make of all this (or the past 10-15 years of my life right now) and I really want a human opinion.

I’ve been relying on google Gemini to aggregate a lot of information together for me but at this point I think I’ve reached the end of its usefulness for this kind of thing and I’m just going around in circles now.

I don’t know what to do.

For the past 10 years or so, I’ve had a chronic burning sensation on the top of my head that is severe enough to basically keep me from getting a job.  It’s very uncomfortable to the point where I’d have to get ice and put it on the top of my head.

I actually don’t have a huge myriad of symptoms like I’m reading here how some people can - it’s just awful body wide inflammation (it likes to start at the top of my head and work its way down my neck, spine and it radiates out if it gets worse).

I have other neurological problems like OCD and anxiety that manifest and increase alongside the pain.

In hindsight, I believe I’ve probably had these symptoms throughout the majority of my life and only now they are becoming unbearable.

As I type this right now I feel like I am covered in rug burns.  In an attempt to possibly relieve myself of this pain finally I started looking for low histamine cooking recipes.  Last night I cooked chicken breasts in a sauce pan filled with water, celery, carrots, lemon slices, and onion.  I also drank a mandarin yuzu Spindrift (more citrus).

I let it cook for maybe 15 minutes, not long (that’s where the histamine comes from, right? When it’s too long?).

Unfortunately last night I had awful anxiety and couldn’t sleep until 5 or 6 in the morning.  I actually didn’t have tons of pain - at least not until the anxiety portion of the episode let up.  Then my head started burning again and as I’m typing this at 4 in the afternoon it’s still burning and I can feel patches of my skin being inflamed too.

I’m really, really, upset here because I don’t understand what is happening.  I did read that citrus fruit can give you histamine problems but I cooked a salmon piece in literally the same way a couple of days ago and was fine.  Are you telling me some days you just react and some days you don’t?
It was an awful experience and I feel awful right now - anxious still and now even afraid to try cooking like this again.

I was getting really hopeful.  I’d cooked really plain for a few nights - literally just chicken in water (no pain or anxiety).  I’m honestly trying to remember what I ate over the past couple of days and I can’t that’s how stressed I am (I need to keep a food journal).

Again, the pain is so bad - always just burning at the top of my head, right in the middle.

I’m on medication too.  When I was 20 years old I had to go to the hospital for an anxiety attack that I didn’t come out of.  I remember pacing back and forth in a room telling the nurses that I couldn’t stop thinking.  They put me on tons of sedatives but I wouldn’t fall asleep.

Eventually a doctor who was making the rounds put me on Depakote, which I am on to this day.  The medication is primarily an anticonvulsant (not applicable to me) and mood stabilizer, however, if you google this medication and auto-immune suppression, it has been recently observed that this medication actually calms systemic inflammation.

I think this is an important piece of the puzzle.  About ten years ago (after being on the drug for about 5 years, I’m around 25 at this point), I attempted to titrate off of it to see if I still needed it.  The results were disastrous.  Over a period of months my entire body inflamed from head to toe like fire - it was constant, no lapses, no rest.  I quite literally nearly lost my ability to actually sleep and was on opioid pain killers every 4 hours to numb the burning (so I could kind of sleep).

The lowest I ever got was to 500 milligrams of the 1500 milligrams ER dosage.

There were very strange occurrences that happened when I lowered my dosage:

• I had regular tightness and pain in my left side chest and left arm, and we went to the emergency room on several occasions where I was assured I was not actually having a heart attack.  This appeared to be the case - as these particular symptoms persisted for months (if not one or two years) during and after this experience.
• I went to the hospital once for the pain - but it was bad this time.  I was basically put into a small room while I just screamed and cried (like, snot dripping out of my nose) because of the burning I felt all over my head, neck and back.  They ran me through a catscan because they just didn’t know what else to do with me - which of course returned nothing.
• When I would eat meals (this was strange), my left upper side (maybe where the stomach is?) would start to burn and hurt.
• Additionally about hunger - I've always had a low appetite my whole life, and after being put on the depakote I started having a normal appetite and was able to gain some more weight by eating (I hover around 125 pouns). When I lowered the does, my appetite dropped and so did my weight to around 110 pounds).

When I was in this state sleep was very difficult and mostly only achievable through heavy sedation (the opiod pain killers).  I had this super-high constantly present level of anxiety.  It was very scary, I basically just lost consciousness and then woke up four hours later and sat in the burning inflammation, anxiety, and other irrational thoughts that occurred as my mind succumbed to high-levels of OCD.  Eventually, after (I can’t remember how long exactly) maybe several months of this I finally just had to admit that I needed the medication.

I still remember the night I re-administered the regular dosage of Depakote.  I was sitting on the couch rocking back and forth, everything burning, so much pain, couldn’t sleep.  As soon as I popped those extra pills, within approximately 15 minutes the pain started to alleviate.

Things improved but basically I still was mentally messed up after this and I still had enough pain where I was not able to function properly.

Eventually I was stabilized on a treatment (at that same doctor mentioned befores clinic) called Transcranial Magnetic Stimulation (TMS), where they use electricity pulses on my brain.  I’m not really sure how this factors in here but it basically helped with the pain and anxiety.  I am receiving this treatment to this day.  It works but I’m tied to it, and I would like to solve my health problems and find out what exactly is wrong with my body.

When I started feeling better, this is when I started looking at what are some things I can do to actually help myself.

I removed sugar from my diet, we’d never tried an elimination diet before and I figured what did I have to lose.  The results were a complete surprise.  After one month of no sugar, my regular energy levels increased (it was normal for me to be regularly sluggish), and also my mood improved.  Today, if I have too much sugar, I become very ornery and irritable.

Another crazy thing that happened after 6 months of no sugar, is that my heart arrhythmia (that I’ve basically had my whole life), actually just went away.  I was checking my pulse one day and I was like “what the hell?!” - It was just gone.  And it continues to beat normally to this day.

Then came the gluten (I’m negative for celiac).  I kinda got depressed and just started eating noodles and white bread again (I had half-assedly removed gluten from my diet previously) and during that two week period, my anxiety increased significantly.  I simply just took a look at the foods I was eating over that period and it seemed like the most obvious thing so I made the adjustment.  This seemed to be just a good thing to keep out, as consuming leads to more anxiety symptoms.

However, this is where things get confusing.  I was still having very severe, otherwise unexplained anxiety symptoms - like the bad feelings, the ones reminiscent of when I had to go to the hospital for “not being able to sleep, or stop thinking.”

At first, the target was nightshades.  I noticed things like paprika and salsa (basically no more tacos) definitely gave me problems.  And I did my best to cut them out and I think it was fine for the most part.  But then, other weird things would happen.

This happened actually just recently maybe a month ago and has given me major ammunition for my suspicion towards histamine intolerance.

I ran out of turkey cold-cuts for my sandwiches (gluten free sourdough bread) and so I just made a sandwich out of ham cold cut slices.  I did this for two nights in a row and each night I had awful anxiety and did not get much sleep, then on the third night I had a coney hotdog (plain on the gf bun) and that night I had such an intense anxiety attack it was like a flash back to years ago.  I was up to like 5AM, tight chest and arm - I knew from the experiences before I wasn’t having heart problems, but it’s still scary when it happens and of course sleep is impossible because my mind is in a hyper-aware state.

This three day experience (after googling/Gemini) is what led me to this whole histamine thing especially.  It seemed very consistent.

(Oh, and I also have that thing where I get a runny nose when I eat sometimes)

And at the end of the day - I’m just trying to make the burning stop.  It’s all the time, I just don’t understand.

I started trying to avoid the skillet and stovetop because when I started cooking with oil and meat I noticed I had pain almost every night (although, the anxiety itself wasn't actually that bad, it's mostly the pain here).  I have more pain with olive oil, and I have less pain now that I’ve switched to avocado oil; but it’s still there.

Something I’lll cook regularly is that I’ll defrost some shrimp, salt and pepper them, cover them in cornstarch, then egg, then sugar free gluten free bread crumbs and the fry them all up in avocado oil on the stove in a pan along with some steamed and then also oil pan fried brussel sprouts.  I almost always have some sort of pain when I cook in such a way.

I also had pain when I cooked just a lamb chop with no oil in a skillet (although this is inconclusive because I had a regular potato that night which I have not ruled out nightshades).

I was hoping cooking with water and the oven would lessen the pain, and it actually kinda did for a few nights (or at least I thought), but then out of nowhere like last night after I cooked chicken in the sauce pan now I have anxiety and pain.

I’m afraid I’m hurting myself and I don’t know what to do here.

I bought a book “The 4-Phase Histamine Reset Plan” by Dr Becky Campbell off of amazon and there are a lot of things that look like I need to look into.

I’ve been assuming I have leaky gut for years now - but there’s things like SIBO, Helicobacter Pylori, Mast Cell Activation Syndrome…

I don’t look forward to having to twist my doctor's arm to get work done, but I guess that's the next step.

I mean… I guess I just schedule an appointment and bring up SIBO, MCAS, and histamine intolerance or that one infection I mentioned earlier?

Oh, this is something I remembered (and why I suspect SIBO) from reading about the signs): I've had a low appetite my entire life and always struggled to gain weight, especially by eating. Also, a couple of years back I completely lost my appetite come the fall to winter months (this has historically been a bad time for me when the sun goes away). I had to remember to eat because I wasn't feeling hunger. Also come the winter months I would have severe and months long episodes of vertigo. Basically during the winter months if I had to keep my head almost perfectly straight, and tilting it 15 degrees or more would cause the room to start spinning and naseau (can't spell this damn word).

Another thing is that both my and my sister have severe natural B12 levels in our body (malabsorption?) She needs to inject hers, I can use under the tongue (sublingual). After I was supplemented on the B12, the vertigo episodes haven't returned and also I have a pinch more energy.

I’m just trying to find out where this burning is coming from.

Is histamine intolerance that inconsistent when it comes to recovery?  I got really freaked out last night when all I made was my own broth in water and had horrible anxiety.

It was so bad I wouldn’t really want to try to make that again.  Is it really just the lemon and citrus drink that could have done that?

What are your opinions based on my experience - am I even barking up the right tree here?

I can keep trying with this low histamine diet thing but I'm afraid after last night. I could just try pulling out all the citrus but it just seems odd to me that that whole episode could have been made that bad by just simmering the chicken in the broth like that. It wasn't as bad as the cured-meat situation (ham and conie dog), but it was still bad and I couldn't get to sleep.

I'm honestly wondering how much of this even just happens during my sleep if I get to bed before 12AM because a lot of these symptoms happen between 1AM-5AM.

---

So there's kinda maybe another detail - I went to a clinic when I was 25ish and they scanned the bloodflow levels in my brain. It was a functional medicine clinic (Dr Amen, if I remember?). The scan results showed that the front of my brain (prefrontal cortex) was not metabolizing above the baseline. The practitioner's own words were (to me and my mother): "Has your son ever been in a car accident before?" after seeing the results. Additionally the central regions of my brain were hyper-active (so all the anxiety zones).

But another thing they did there was do some other blood tests. I actually had marker for a tick bite or some kinda tick infection. However, we have no idea when, how or where this occured. I live in a state in America where we have deer and ticks and it wouldn't be unheard of if somebody got bit. I was was put on some antibiotics for good measure and then also was sent to a limes (lymes?) disease clinic and I was told point blank by the doctor there that I didn't have it. I can more or less agree here. I'm pretty much fine in that respect and I'm not sickly or weak in that sense.

Hi all! I have been taking Allegra and 80mg of famotidine daily for my histamine/possible mast cell issues as instructed by my allergist. It’s done wonders for my histamine intolerance, but one thing that’s been a major issue has been dryness everywhere. Ever since I started taking it my skin, my hair, my digestive tract, have all shown signs of extreme dryness. It’s so bad to the point my allergist tested me for Sjorgen’s due to seeing how much dead skin was noticeable on my clothes despite moisturizing daily (it came back negative). I’m constipated all the time, my hair is breaking off extremely bad and is constantly dry no matter what shampoo and conditioner I use or any masks (plus a lot of the scents trigger my histamine issues), there’s always dead skin on me, and my eyes stay slightly irritated 24/7. My allergist doesn’t think it’s my medications, so I’m not really getting any help, but per the timeline of this all happening that’s the only thing that has changed in my routine. Has anyone else had this issue? If so, how did you help it/treat it? Thank you all for reading and any advice!

Hi! I’m in search of a doctor - open to different kinds of- based in NYC who is deeply knowledgeable about histamine issues and MTHFR gene mutations. I’m looking for someone who won’t stop until they help me figure out what is going on, and has the belief system and expertise to do so. Would love any and all recs! Thank youuuuu so much ahead of time

I'm trying to work on gut health foe other health issues and needless to say, SEED has completely worsened things.

I'm now breaking out in hives any time I get hot. I've stopped the probiotic and it's still happening. From what I've read, there's strains in it that are high histamine. Just want to warn others.

Hi there, I am trying to wrap my mind around what couldve caused my HI.

I firmly believe that the root cause of my HI is gut health.

However, the months before my symptoms started, I was living the healthiest lifestyle of my life.

I was exercising 2-3x a week, I was eating lots of legumes and protein, drinking green tea and eating saukerkraut on a regular basis.

I even lost about 10kg of weight (intentionally).

And then my symptoms started.

The one thing I can think of is that the lifestyle caused a change in the system and something went wrong but I am really unsure if thats even possible.

If I was eating / living in a way that was terrible for gut health I wouldnt be puzzled, but I wasnt.

So I wonder what other peoples stories are, and whether someone has a hypothesis about mine.

Thank you.

My story with gastritis /LPR / histamine issues can anyone relate? Could my nervous system be the culprit? Could the lining of small intestine heal this be a solution?

Past 4 years I got the gastritis symptoms and Laryngael reflux (LPR) past 5 years and histamine issues

My histamine issues are nasal congestion when eating fermented foods for example or high histamine foods. Also sleep issues

But I remember years previously I felt super stressed and unhappy with my life. For some reason my sleep has gotten bad. I would always wake up 3 hours in sleep and I did notice I would fall asleep and still end up with 7 hours slept. But I noticed the sleep was getting worse I would wake up 2-3 hours in sleep and then unable to fall asleep again

I was also dealing with injuries that prevented me sleeping. For example I had a wrist injury that was causing pain during sleep. So I think I developed anxiety and poor sleep from stress/injuries

This eventually lead to something happening to me. When I ate really spicy food, I ended up getting dizzy and vertigo symptoms during the meal. I was having extreme panic attacks and worried about my health next few months because I had no idea why that happened

I even had a very weird hyperacusis moments (extreme sensitivity to sound), my nervous system was fully shot. Hearing things like a fork on a plate gave me extreme panic because it seemed loud.

That eventually led to the gastritis/reflux diagnosis and I have been struggling ever since

In the early years of gastritis/LPR I have tested for h pylori through stool and blood test they both came out negative. I still wonder if my stool was false negative because I did have Diarhea twice when I took it

At my worst in 2023 I lost 20 pounds. I could barely put food down my stomach was very irritated. I did some moments of Pepcid and PPI and it didn’t help much. I relied on alot of natural supplements like DGL.

What made me gain weight and heal: Nervous system regulation

For some reason when I went on vacation in 2024, my mind switched. I became happier, less anxious, less worrying about symptoms. I was eating airplane food while happy and I did end up getting super gassy after the flight but still I felt good in general

First week of vacation was miserable I’m assuming the stress made my throat symptoms and stomach symptoms worse. 2-3 weeks in the vacation, I even noticed my LPR throat symptoms vanished completely. My voice returned, I sounded normal and not strained. Also I was living in an Airbnb no carpet apartment so I wonder if that was helping my allergies and what not

4 week vacation I noticed I gained 12-13 healthy pounds back. I was eating normal food there I wasn’t eating super healthy. I think I was just happier in my life and my digestion was finally working and maybe the stomach lining was healing?

Anyways back to 2025 I came back home and I noticed my symptoms were coming back like the voice hoarseness from silent reflux, the indigestion, ect. For some reason at my home I feel unhappy because people around me are always arguing. I remember moments in the past where I would leave the house completely after hearing them argue. Is this a sign my nervous system is not tolerating the environment?

2026 I took a PPI for 2 months 40 mg to help heal my “voice”. I went to the voice specialized ENT and he said he doesn’t see any signs of reflux. Even though I still had the strained voice and voice pain. He said my vocal cords looked healthy. After he told me that my voice pain instantly went away. Is this another nervous system sensitivity ? He seems to think it’s functional like muscle tension dysphonia because I sound fine in one language and strained in another. But overall I have felt much better with my weight back and I was sleeping fine I wasn’t getting throat symptoms in bed anymore or stomach sensations, I felt healed

I officially tapered off PPI and had no issues with the taper. I got back to my original weight before all the symptoms and distress happened. I was feeling fine in general less stomach symptoms and throat symptoms at night time.

Then something happened

Something loud irritated my ear. I think it’s called acoustic trauma shock. Basically a loud noise triggered my nervous system and ear to be hypersensitive to sounds.

I felt super panic and kept constantly searching up my symptoms and if I did ear damage and what not. Loud noise again affected me and made me tense up badly and feel stressed

I took a supplement called NAC because I thought it would be safe to take to prevent “inner ear damage”. I also ate spicy food during that time and now my symptoms have returned with a vengeance

The dizzy spells, the poor sleep, the anxiety doom wake up after sleeping few hours, the burning in stomach on empty stomach, the bloating. I am now getting bad constipation as well 😞 I am getting that throat feeling again the nonacidic reflux it feels like I have to swallow a liquid feeling in throat that irritates my voice

I’m gonna go to the gastro again soon but I’m hoping any of you have experience or atleast hope I can finally heal based off my experience/environment?

I’m again back to being anxious and looking up my symptoms worrying about the worst health that can happen to me

Also to add:

I have severe dust mite allergy
Mold allergy (cladosporum)

Live in carpet that’s 20 years old

So I wonder if these two are aggravating and causing me to have poor sleep and it’s not only reflux/gastritis related

Pepcid at night empty stomach kinda makes me more anxious I’m clueless on how to heal. Even the Pepcid makes my reflux worse at night because my lower tummy is constantly bloated and I think it causes gaseous reflux to come up from the bloating

I seem to have slow motility in digestion

Also maybe critical thing to add: I was given antibiotics when I was younger 15-16 for acne. They put me on them for so long. Ever since then I developed rosacea in face.

To add: blood levels been fine overall but last few years I noticed

Iron was 55 Ferritin 145 Hemoglobin 13.9 MCV 88 FeSat 23% TIBC 235
My iron was 80ish before and Iron is absorbed in the first part of small intestine

Ketotifen for the reactions , Metropolol for the palpations and now being receive clonidine for the alertness and weird anxiety that prevents me from sleeping. I’m already so drowsy and seem like I can’t function on ketotifen , Metropolol is giving awful PVCs and I’m scared of clonidine cause it supposed lowers blood pressure and heart rate which I already have the Metropolol for. I just don’t know what to do.

Especially after eating foods

You need sufficient copper to make DAO enzyme that help breakdown histamine in the body. Does it make sense that histamine intolerance therefore increases the demand for copper?

I had SIBO causing inflammation in my gut. I noticed that I would need to supplement up to 10,000 IU of D3 daily to keep my levels above 30ng. Since addressing the SIBO I haven't supplemented with any D3 in over 2.5 months and my D3 have kept steady at around 36ng. I was thinking maybe the it's the same with copper, the histamine intolerance has basically depleted my levels.

Hi guys! Are there any actual “testing” that can test for histamine intolerance? I can’t tell if I have it or not. I have a lot of similar symptoms but sometimes I flare and have anxiety and feel off after certain foods but other times I feel fine. I don’t know what to do. Do stool tests help know? If so any recommendations? Any urine or bloodwork? Would love any insight for this :)

What lab/company does the testing? I keep seeing folks on here in the EU being able to get their DAO levels tested, but I can't find a practitioner in the US who knows how to order it anywhere - if that's even possible here.

Thank you in advance!

Hi everyone! I wanted to post an update for anyone who has followed my story, commented on my previous posts, or offered advice. I truly appreciate everyone who has taken the time to help me navigate all of this.

A little background:
In May, I was hospitalized with a serious bacterial infection (streptococcal bacteremia) and received three weeks of IV antibiotics (ceftriaxone). After recovering, I was eating completely normally without any food reactions.
A couple of months later, I developed a UTI and went through another 28 days of antibiotics. Around this time, I started experiencing some very unusual symptoms that seemed to appear almost overnight.
I began having episodes of facial flushing, warmth, and a strange feeling of internal inflammation or pressure, sometimes accompanied by sudden congestion. Certain foods seemed to trigger these episodes, but the reactions were extremely inconsistent. I could tolerate something one week and react to it the next.

I also started developing small, occasional hives or red spots, usually on my hands or arms. They aren’t widespread and often disappear within minutes.
Naturally, I started wondering whether this could be histamine intolerance, mast cell activation syndrome (MCAS), or something related to my gut after all those antibiotics.

Where I’m at now:
I’ve been following a low-histamine diet for several weeks, mostly consisting of ground turkey, rice, and potatoes. I’ve slowly started expanding my diet and have successfully reintroduced broccoli, carrots, and bread.

Since starting the low-histamine diet, I haven’t experienced any more facial flushing or those strange food reactions. I do still occasionally experience mild hives.
I recently saw an allergist whose website specifically mentions expertise in mast cell disorders. She explained that my reactions do not appear to be true IgE-mediated food allergies, and she does not believe I have MCAS based on my history and evaluation, although I still have questions about it.
She mentioned that my body may simply need time to recover after everything it has been through. She prescribed Zyrtec and famotidine twice daily to help manage the urticaria (hives).

Now for my latest update:
I recently went to a gastroenterologist to investigate whether my gastrointestinal health could be contributing to some of these symptoms, especially after so much antibiotic exposure.
She ordered stool testing, including C. difficile, and I tested positive for C. diff. Now I’m facing another course of antibiotics, which is discouraging considering how many I’ve already taken this year.
I asked my GI doctor whether C. diff or the disruption to my gut microbiome could have anything to do with the flushing or unusual food reactions I’ve experienced. She told me that C. diff would not explain those symptoms.
I’m not trying to assume that everything is connected, but I can’t help wondering whether the timing of all these antibiotics, the changes in my gut, and the sudden onset of these reactions could be related somehow.

My questions for anyone who has experienced something similar:
Has anyone developed flushing, hives, or unusual food sensitivities after prolonged antibiotic use or a C. diff infection?
Did you notice any changes in your ability to tolerate foods while recovering from C. diff?
Did your reactions eventually improve as your gut recovered?

Has anyone initially suspected histamine intolerance or MCAS but later discovered that a gastrointestinal issue was contributing to their symptoms?

I’m still trying to understand what’s happening to my body and distinguish between possible mast cell involvement, temporary histamine sensitivity, and gastrointestinal issues. I know symptoms can overlap, which makes everything much more confusing.

Thank you again to everyone who has shared their experiences or offered support. It’s been a difficult few months, and hearing from others has helped me feel less alone in navigating all of this. ❤️

We can do so much for HISTAMINE but nothing can be done for TYRAMINE... but since I am slow MAO-A meaning I don't break down and metabolize tyramine well I did some digging and learned a lactobacillus species of the strain Plantarum actually degrades Tyramine. Sounds cool and worth a try.

Mechanism:

probiotic strain Lactobacillus plantarum 299v (LP299v) degrades tyramine through extracellular and intracellular enzymatic oxidation, breaking down the amine before it can be absorbed across the intestinal wall

Oddly enough the 'good belly' drink brand makes a pure capsule of 299v so I ordered some to try. Plan is take it at same time as high tyramine meal.

Side note: there are other species of plantarum which may not work to degrade tyramine so the 299V may be needed.

Is this like a regular side effect? I itched before but now it’s more whenever I take it ? It’s been about 4 days since starting

Oh my god, I haven't felt such emotions in at least 12 years.

Not long ago someone on this subreddit shared that they got a relief from HI thanks to lactoferrin, so I decided to give it a try too. I mean, I've spent so many thousands of euros on my health, so one supplement bottle won't change much.

I have quite a few issues with my gut (many food sensitivities, mild gastritis, bile reflux, etc) so I wasn't expecting immediate miracles in that area.

But interestingly, just a couple of hours after taking the first 250mg dose I noticed that something shifted in my nervous system. Out of nowhere, the constant sense of emptiness and dread was replaced by a force of positivity and hope that accompanies almost every thought and feeling. I can be literally sitting doing nothing, and this inner aura of wellness just starts to envelop me.

While my digestive issues and HI are still there, but they also seem to be affected by this shift in how I'm feeling emotionally.

I read in one article (link: https://pharmd.substack.com/p/i-have-covid-what-should-my-kids) that there's a protocol of taking 500mg of lactoferrin two times per day, so I've been doing the same for the last week, and I'm feeling even better now mentally.

My theory is that I might have some viral infection or something similar, and lactoferrin is doing something to it. Or perhaps it's affecting the gut-brain axis in some way. I plan to talk to a doctor(s), but I imagine it won't be easy to find someone knowledgeable in this.

Note: I'm taking apolactoferrin (one of the most popular brands that starts from letter J)

I am riding the struggle bus for over a decade. I took some real time to figure out it was histamine Anyways I had AI scan this sub and come up with TOP root causes. Hoping to save someone some time and help them heal. Best of luck my friends and lets hear your root causes, how you figured it out and how you have healed and or where you are on your journey.

HISTAMINE INTOLERANCE MASTER GUIDE: Symptoms → How to Identify It → Root Causes → How to Heal

I wanted to put together one master post for everyone dealing with histamine intolerance.

Important: Histamine intolerance is probably not one disease with one cause. Think of it more like a bucket overflowing.

Your body makes histamine.
Food adds histamine.
Gut bacteria can make histamine.
Mast cells can release histamine.
DAO and other enzymes remove histamine.

Symptoms appear when:

HISTAMINE COMING IN/BEING RELEASED > YOUR BODY'S ABILITY TO BREAK IT DOWN

The goal shouldn't just be to eat low histamine forever.

The goal is:

1. Lower the histamine load temporarily
2. Figure out WHY your bucket is overflowing
3. Fix what is fixable
4. Slowly regain food tolerance

PART 1 — WHAT CAN HISTAMINE INTOLERANCE FEEL LIKE?

You do NOT need to have hives.

Different people can have completely different symptoms.

DIGESTIVE

• Bloating
• Gas
• Burping
• Abdominal pain
• Reflux/heartburn
• Nausea
• Diarrhea
• Constipation
• Feeling overly full after meals
• Food suddenly seeming difficult to digest

BRAIN / NERVOUS SYSTEM

• Migraines
• Headaches
• Brain fog
• Anxiety after eating
• Irritability
• Feeling "wired"
• Internal restlessness
• Poor concentration
• Dizziness
• Trouble sleeping
• Waking up in the middle of the night
• Possibly tinnitus/ringing in the ears in some people

SKIN

• Itching
• Hives
• Flushing
• Red face/chest
• Rashes
• Burning skin

NOSE / EYES / LUNGS

• Runny nose after eating
• Congestion
• Sneezing
• Watery/itchy eyes
• Coughing
• Wheezing in some people

HEART / CIRCULATION

• Heart racing after eating
• Palpitations
• Feeling your heartbeat strongly
• Lightheadedness
• Hot flashes/flushing

GENERAL

• Fatigue
• Feeling awful after certain meals
• Exercise intolerance during flares
• Symptoms that become dramatically worse after alcohol
• Symptoms that vary depending on stress, illness, sleep, menstrual cycle or gut health

PART 2 — HOW DO YOU KNOW HISTAMINE MAY BE INVOLVED?

There is no perfect single test.

Look for a PATTERN.

CLUE #1

Symptoms repeatedly appear after high-histamine foods such as:

• Aged cheese
• Fermented foods
• Alcohol
• Wine
• Beer
• Cured/processed meats
• Smoked meats
• Fish that isn't extremely fresh
• Bone broth/long-cooked meat stock
• Leftovers stored for long periods

Individual tolerances vary enormously.

CLUE #2

Eating very fresh, lower-histamine foods for a short period noticeably improves symptoms.

CLUE #3

Reintroducing higher-histamine foods makes symptoms return.

CLUE #4

DAO taken before a high-histamine meal noticeably reduces your symptoms.

That does NOT prove your root cause. It is simply another clue that dietary histamine may be involved.

CLUE #5

Symptoms are dose-dependent.

One bite = maybe nothing.

Several histamine foods together = reaction.

This is the "histamine bucket" concept.

PART 3 — BEFORE BLAMING HISTAMINE

A LOT of diseases can imitate histamine intolerance.

Consider ruling out things such as:

• True food allergy
• Celiac disease
• Inflammatory bowel disease
• Thyroid problems
• H. pylori
• Gastritis/ulcer disease
• SIBO
• Other GI disease
• Medication side effects
• MCAS
• Nutritional deficiencies

Severe throat swelling, difficulty breathing, fainting or suspected anaphylaxis is NOT something to troubleshoot on Reddit. Get emergency medical care.

PART 4 — THE ROOT-CAUSE CHECKLIST

This is the important part.

1. DAMAGED OR INFLAMED GUT LINING

DAO — one of the major enzymes responsible for breaking down food histamine — is produced heavily in the intestinal lining.

If that lining is inflamed or damaged, histamine tolerance may drop.

Clues

• GI symptoms
• Recent intestinal infection
• IBD
• Celiac disease
• Chronic diarrhea
• Significant gut inflammation
• Symptoms appeared after a severe GI illness

What to do

Treat the actual source of inflammation.

Don't spend your life simply suppressing histamine while ignoring the bowel disease underneath it.

2. GUT DYSBIOSIS

Some intestinal microbes can produce histamine and other biogenic amines.

A disrupted microbiome may therefore increase your total histamine burden.

Clues

• Started after antibiotics
• Gas/bloating
• Food intolerance
• Bowel habits changed
• Symptoms began after GI infection
• Probiotic foods make you much worse

What to do

Find out WHY your microbiome became disrupted.

Avoid randomly taking ten probiotics because some probiotic strains may be poorly tolerated.

Work on:

• Diet diversity as tolerated
• Normal bowel movements
• Adequate nutrition
• Treating underlying GI disease
• Avoiding unnecessary antibiotics
• Slowly expanding foods as you improve

3. SIBO

Small intestinal bacterial overgrowth can potentially contribute to bloating, altered motility, intestinal inflammation and histamine problems.

Clues

• Major bloating after eating
• Gas
• Distention
• Constipation or diarrhea
• Symptoms particularly after carbohydrates/FODMAPs
• Feeling better while fasting/not eating

How to identify

A hydrogen/methane breath test is commonly used, although testing isn't perfect.

What to do

If SIBO is actually present:

Treat the overgrowth AND figure out why it happened.

Possible underlying contributors include:

• Poor intestinal motility
• Constipation
• Structural problems
• Certain medications
• Other digestive disease

Simply killing bacteria repeatedly without addressing the cause can lead to recurrence.

4. POOR MOTILITY / CONSTIPATION

Food and bacteria sitting around longer can create an unhealthy intestinal environment.

Clues

• Constipation
• Incomplete bowel movements
• Significant bloating
• Slow digestion
• SIBO that keeps returning

What to do

Work on restoring normal motility:

• Hydration
• Movement/exercise
• Enough food
• Appropriate fiber if tolerated
• Magnesium when appropriate
• Treat thyroid problems if present
• Identify medications that slow the bowel
• Treat pelvic-floor dysfunction when present

5. LOW DAO ACTIVITY

Some people simply don't break down dietary histamine efficiently.

This may be temporary or partly genetic.

Clues

• Very clear reactions to aged/fermented foods
• Alcohol is horrible
• DAO noticeably helps
• Other gut problems are present

What may help

• Temporarily lower dietary histamine
• DAO before higher-histamine meals
• Repair/treat underlying gut disease
• Correct relevant nutritional deficiencies
• Reduce alcohol

Think of DAO supplements as a tool, not necessarily the cure.

6. GENETICALLY LOWER DAO

Some people have genetic variants affecting DAO production/activity.

Clues

• Histamine problems seem lifelong
• Strong family history
• No obvious triggering illness
• Genetic testing finds relevant AOC1 variants

What to do

You cannot change the gene.

But genetics are not always destiny.

Reducing other contributors may greatly increase your overall tolerance:

• Gut health
• Alcohol
• Medications
• Nutritional status
• Total histamine intake

7. POOR DIGESTION / POSSIBLY LOW STOMACH ACID

This gets discussed a LOT here.

Adequate stomach acid helps digest protein, absorb nutrients and suppress excessive bacterial growth.

Clues sometimes reported

• Constant burping
• Food sitting heavily in stomach
• Early fullness
• Bloating
• Protein difficult to digest
• Symptoms started after acid-suppressing medication

Important

Symptoms alone CANNOT reliably diagnose low stomach acid.

Heartburn can occur with both too much acid and completely different problems.

Do NOT automatically start swallowing large doses of betaine HCl.

If low stomach acid really exists, figure out why.

Possible contributors include gastritis, H. pylori, medications and other digestive conditions.

8. H. PYLORI / GASTRITIS

These can affect normal stomach function and digestion.

Clues

• Upper abdominal pain/burning
• Nausea
• Frequent burping
• Early fullness
• Reflux
• History of ulcer

What to do

Test appropriately.

If H. pylori is genuinely present, treat the infection rather than trying to supplement your way around it.

9. CELIAC DISEASE

Celiac disease damages the intestinal lining.

That makes it a very logical condition to exclude in someone with major food intolerance/GI symptoms.

Clues

• Chronic digestive problems
• Nutrient deficiencies
• Weight problems
• Autoimmune history
• Symptoms after gluten

What to do

Get tested BEFORE going permanently gluten-free because removing gluten can interfere with testing.

If celiac is confirmed, the treatment is a strict lifelong gluten-free diet.

10. IBD / CHRONIC INTESTINAL INFLAMMATION

Crohn's disease, ulcerative colitis and other intestinal inflammation can impair the intestinal environment where DAO normally functions.

Clues

• Blood/mucus in stool
• Chronic diarrhea
• Abdominal pain
• Unexplained weight loss
• Known IBD

What to do

Control the underlying inflammatory disease.

Low-histamine eating may decrease symptoms but does not replace treatment of IBD.

11. NUTRIENT DEFICIENCIES

DAO function is associated with several nutrients, particularly:

• Copper
• Vitamin B6
• Vitamin C

Other deficiencies can also cause symptoms that look like histamine intolerance.

What to do

TEST when possible.

Correct actual deficiencies.

Don't assume:

"Histamine problem = take lots of copper."

Too much of a nutrient can also cause problems.

12. TOO MUCH ZINC → COPPER PROBLEMS

Large amounts of supplemental zinc can interfere with copper absorption.

Clue

Long-term/high-dose zinc supplementation + low copper status.

What to do

Stop blindly megadosing minerals and check your actual status.

13. ALCOHOL

Alcohol is a double hit.

It can add to the histamine/biogenic-amine burden AND interfere with histamine degradation.

Clue

Wine/beer/alcohol absolutely destroys you.

What to do

Take alcohol completely out while recovering.

Retest tolerance much later.

14. MEDICATIONS

Some medications may interfere with DAO activity or indirectly worsen histamine problems.

Others alter:

• Gut bacteria
• Motility
• Stomach acid
• Mast-cell activity

What to do

Review ALL medications and supplements with someone who understands pharmacology.

Do NOT abruptly discontinue necessary prescriptions because of a Reddit post.

15. POST-INFECTIOUS / LONG COVID

Many people report histamine-type symptoms appearing after COVID or another significant infection.

Potential contributors may include:

• Immune dysregulation
• Gut microbiome changes
• Autonomic dysfunction
• Mast-cell activation
• Post-infectious GI problems

Clue

You were fine → infection → suddenly couldn't tolerate foods anymore.

What to do

There currently isn't one magic "long-COVID histamine cure."

Identify which system is actually affected and treat that problem.

16. MCAS / MAST-CELL ACTIVATION

Histamine intolerance and MCAS ARE NOT THE SAME THING.

Histamine intolerance generally describes difficulty handling histamine, especially dietary histamine.

MCAS involves inappropriate mast-cell mediator release.

MCAS becomes more suspicious when

• Reactions happen without food
• Smells/heat/exercise/stress trigger attacks
• Multiple organ systems react simultaneously
• Significant flushing/hives
• Wheezing
• Swelling
• Tachycardia
• Severe episodes seemingly out of nowhere

What to do

Work with an allergist/immunologist familiar with mast-cell disease.

Treating MCAS can involve:

• Trigger management
• H1 antihistamines
• H2 antihistamines
• Mast-cell stabilizing medications

depending on the individual.

17. STRESS / AUTONOMIC NERVOUS SYSTEM DYSREGULATION

This does NOT mean your symptoms are imaginary.

The nervous system and digestive tract are intimately connected.

Chronic fight-or-flight can affect:

• Gastric secretion
• Intestinal motility
• Gut permeability
• Immune signaling
• Mast cells
• Sleep
• Pain perception

Clues

• Symptoms explode during stressful periods
• Eating while anxious worsens everything
• Poor sleep dramatically lowers food tolerance
• Symptoms improve on vacation
• Meditation/breathwork/exercise noticeably improves digestion

What to do

Treat this as another physiological system worth healing:

• Sleep
• Regular movement
• Time outside
• Meditation
• Slow breathing
• Therapy when relevant
• Trauma treatment when relevant
• Social connection
• Stop living in constant fight-or-flight if possible

This may be part of the solution without being the entire explanation.

18. HORMONES

Histamine and estrogen interact.

Some women notice dramatic differences across their menstrual cycle.

Clues

Histamine tolerance predictably worsens:

• Around ovulation
• Before/during menstruation
• Pregnancy
• Perimenopause

What to do

Track symptoms against the cycle.

If the pattern is dramatic, investigate genuine hormonal disorders rather than blindly taking hormone supplements.

19. THYROID / METABOLIC PROBLEMS

Hypothyroidism can slow GI motility, which can contribute indirectly to dysbiosis/SIBO.

Clues

• Constipation
• Cold intolerance
• Fatigue
• Dry skin
• Slow digestion
• Weight changes

What to do

Check thyroid function and treat true thyroid disease.

20. MOLD / ENVIRONMENTAL EXPOSURE

This is heavily discussed in histamine/MCAS communities.

Mold exposure can absolutely cause respiratory/allergic symptoms and certain molds can cause disease.

The controversial part is claiming that almost every case of histamine intolerance is caused by hidden "mycotoxin toxicity."

Reasonable approach

If your home/workplace has obvious:

• Water damage
• Visible mold
• Musty odor
• Symptoms that improve dramatically when you're away

investigate the BUILDING.

Fix ongoing exposure first.

Be much more skeptical of extremely expensive detox programs based solely on questionable urine testing.

21. SIFO / FUNGAL OVERGROWTH

Fungal overgrowth is another frequent Reddit explanation.

It may exist in some people.

It should NOT be assumed simply because you have bloating or a white tongue.

What to do

Establish reasonable evidence that fungal disease/overgrowth is actually present before repeatedly using antifungals.

22. PARASITES / CHRONIC INFECTIONS

Yes, infections can disrupt the GI tract.

No, everyone with histamine intolerance does not secretly have parasites or Lyme disease.

Clues

• Exposure/travel risk
• Persistent diarrhea
• Abnormal testing
• Compatible symptoms
• Known prior infection

What to do

Identify the organism.

Then treat THAT organism.

Don't blindly cycle through antiparasitic drugs.

PART 5 — THE SIMPLE RECOVERY PLAN

If you're completely overwhelmed, start here.

PHASE 1 — CALM THINGS DOWN

For a few weeks:

• Eat mostly fresh foods
• Reduce the worst high-histamine foods
• Avoid alcohol
• Avoid repeatedly eating old leftovers
• Freeze leftovers quickly if needed
• Don't massively overeat
• Get your bowel movements regular
• Sleep
• Stop adding random supplements every three days
• Keep a food/symptom diary

The goal is NOT a permanent 15-food diet.

It's to establish a baseline.

PHASE 2 — FIND YOUR PATTERN

Ask:

Mostly GI?

Think harder about:

• Dysbiosis
• SIBO
• Motility
• Constipation
• H. pylori
• Gastritis
• Celiac
• IBD
• Digestion

Mostly allergic-type attacks?

Think harder about:

• Allergy
• MCAS
• Environmental triggers
• DAO/histamine load

Started after COVID/infection?

Think:

• Post-infectious gut changes
• Dysautonomia
• Mast-cell activation
• Dysbiosis

Started after antibiotics?

Think:

• Microbiome disruption
• SIBO/dysbiosis
• Secondary digestive changes

Started after years of PPIs?

Investigate:

• Why the PPI was needed
• Stomach function
• H. pylori/gastritis
• Microbiome/SIBO

Lifelong?

Consider:

• Genetics
• Allergy
• Mast-cell disease
• Chronic GI condition

PHASE 3 — FIX THE ROOT CAUSE

Examples:

SIBO → treat SIBO + restore motility.

Celiac → gluten-free diet → intestinal healing.

IBD → control inflammation → intestinal healing.

H. pylori → eradicate H. pylori → allow stomach recovery.

Constipation → restore motility.

Nutrient deficiency → correct deficiency.

Medication problem → work with doctor to change medication if appropriate.

Alcohol → stop alcohol.

MCAS → treat mast-cell activation.

Moldy building → remove exposure/remediate building.

Post-infectious dysautonomia → rehabilitate autonomic system and treat associated problems.

PHASE 4 — REBUILD TOLERANCE

This part is hugely important.

Once symptoms calm down, slowly challenge foods again.

Don't become afraid of food.

The ultimate goal for most people should be:

THE BROADEST DIET YOUR BODY CAN COMFORTABLY HANDLE.

Not winning an award for eating the lowest-histamine diet on Earth.

ONE HUGE WARNING ABOUT "ROOT CAUSE" MEDICINE

Finding the root cause is a great idea.

But the phrase has also become a marketing machine.

Be cautious when someone tells you:

"Everybody with histamine intolerance has __________."

Especially when the blank is:

• Mold
• Candida
• Parasites
• Heavy metals
• MTHFR
• Lyme
• "Toxins"
• Leaky gut

AND they happen to sell the $2,000 protocol that cures it.

Any of those things may matter in an individual person.

None should automatically be assumed.

KEEP THE BIG PICTURE

The model that makes the most sense to me is:

TRIGGER

↓

gut / immune / nervous-system disruption

↓

more histamine being produced or released + less histamine being broken down

↓

your histamine bucket overflows

↓

symptoms

↓

Then instead of spending your entire life avoiding histamine:

identify trigger → reduce histamine temporarily → repair/treat underlying problem → restore tolerance → expand diet

EDIT: IMPORTANT NOTE ON MCAS

Histamine intolerance and MCAS are not the same thing, although they can overlap.

Histamine intolerance usually means your total histamine load exceeds your ability to break it down, often involving dietary histamine and reduced DAO activity.

MCAS (mast cell activation syndrome) involves mast cells releasing excessive or inappropriate amounts of histamine and other chemical mediators.

A few clues that make MCAS more worth investigating:

• Reactions happen even when you haven't eaten high-histamine foods
• Heat, exercise, stress, smells, medications or temperature changes trigger episodes
• Symptoms affect multiple systems at once — for example flushing + racing heart + diarrhea + wheezing
• Hives, swelling or flushing are prominent
• Symptoms come in unpredictable attacks
• Antihistamines help significantly but diet alone does not control things

MCAS is also more complicated than just "too much histamine" because mast cells release many mediators besides histamine.

So:

Histamine symptoms ≠ automatically MCAS.

And:

A normal tryptase does not automatically rule out every form of mast-cell activation, although MCAS has specific diagnostic criteria and should ideally be evaluated by an allergist/immunologist familiar with mast-cell disorders.

If your symptoms are overwhelmingly meal-related and improve dramatically with lower-histamine foods, digestion/gut/DAO issues may deserve more attention.

If you're reacting unpredictably to food, heat, smells, stress, exercise and medications across multiple organ systems, MCAS deserves a closer look.

LASTLY — PLEASE ADD YOUR EXPERIENCE

If you've significantly recovered, comment with:

1. Your main symptoms

2. What triggered your histamine intolerance

3. Your actual root cause, if you found one

4. How you confirmed it

5. What treatment helped

6. What you tried that DIDN'T help

7. Whether you can eat high-histamine foods again

If enough people answer in that format, maybe we can turn this thread into something much more useful than 10,000 disconnected posts.

Let's build a database of patterns and help the next person figure this out faster.

Hey everyone. I have been dealing with histamine intolerance for almost a year. I’m not sure what caused it or triggered it, but it started right after a loved one’s funeral and some sort of a cold/flu.

These are my symptoms mostly:

- Headaches

- Strange scratchy/pressure sensation behind my eyes, in nose area, sometimes chest

- Brain fog, being unable to form sentences properly, forgetting words

- Fatigue and sluggishness

- General feeling of being unwell

- Sometimes dissociative feeling

- Sometimes anxiety

- Symptoms get much worse during luteal phase (I do also have PMDD)

- I do experience lots of stomach bloating too though I’m not sure if it’s related to this

I often am unable to tell whether I’m getting sick with a cold/flu or whether it’s histamine intolerance picking up. The symptoms are very similar, except there is no fever of course or sore throat.

I notice many foods give me symptoms, how much I sleep, stress affects it a lot, sometimes even showers or exercise gives me symptoms.

I was just prescribed Penicillin V and Metronidazole for an infection in my mouth (after getting my wisdom teeth taken out). I’m on day 5 currently of taking them.

I noticed soon that my energy levels have been higher, I have not been getting headaches (normally I have a headache probably every other day or every day almost) and I feel almost normal? I did get two tiny histamine reactions but they went away quite fast.

It’s making me wonder what could this whole thing be about, why are the antibiotics helping? I kind of wish this would stay :(

Anyone with histamine intolerance and low ferritin?

My question is about heart palpitations and insomnia. Is there a way to distinguish heart palpitations and insomnia caused by low ferritin vs histamine intolerance?

Does anyone know if marshmallows are safe ?

I’m looking to see if this has happened to anyone else here before and trying to figure out the root cause. Yesterday I had what I think is a histamine attack that I confused with a panic attack.

I’ve never had anything like that happen to me before and some of it was brought on by my own actions. I’ve been following a low histamine diet all year and have seen a lot of progress and am currently being worked up by an Allergist for either histamine intolerance or MCAS but as you know these are hard to dx so it’s taking some time.

Yesterday I went to a perfume expo. It was a lot of fun and I smelled probably close to 100 scents. I also had my first drink in almost 11 months yesterday. I know alcohol made my joints hurt before the low histamine diet and honestly we wanted to see if it was still a trigger. I ended up having two drinks bc my friend ordered me a second, I had only planned on having one to test the theory.

Joints started hurting and - like I always do- I took a gummy bc it’s the only thing that helps with the pain. A few hours later I feel absolutely wasted and that freaked me out. Then I had what I thought was a panic attack. I was so scared and my entire body was shaking.

I’m fine now, obviously, other than being embarrassed. Once I was able to reason and convince myself it was a panic attack I took t h H1/2 combo and it slowly started residing. And my joints still hurt today among other things but the looming sense of doom is gone, thank god.

I’m really thinking I was just an idiot yesterday and the scents+drinks was a huge trigger for me that I made worse somehow.

Has this happened to anyone else? I know the scent thing is closely tied to MCAS but I wanted to start here first as I haven’t been dx with MCAS but have been dx with HIT. I didn’t know that histamine attacks were a thing and that they mimicked panic attacks.