What Causes Histamine Intolerance?

Michael Eisenwasser 2 min read

After I connected my symptoms to histamine intolerance, I wanted to know what caused it. The frustrating answer is that there often isn't one clear cause. Several things can contribute at once, and the mix is different for different people.

There's a useful side to that: you may not need to find one clear cause to start feeling better.

Possible factors

Gut problems. A lot of the histamine you get from food is handled in the gut, so gut trouble and histamine symptoms often come as a pair: SIBO, a stomach bug or food poisoning you never quite bounced back from, ongoing IBS-type issues. Some people also find certain probiotics make things worse, though the effect varies by strain and person.

Medications. Some common medications can contribute to histamine problems. Which ones matter for you is a question for a doctor or pharmacist, and never a reason to stop something on your own. It's worth knowing the connection exists, because people rarely connect a years-old prescription to symptoms that feel new.

Hormones. Symptoms that cycle with your period, worsen in perimenopause, or shifted after starting or stopping birth control are a pattern many people notice. More in histamine intolerance and hormones.

Stress. Some people notice more symptoms during stressful periods, even after meals they usually tolerate. More in why stress makes histamine symptoms worse.

A starting point you can name. Some people remember their symptoms beginning after an illness, food poisoning, surgery, pregnancy, or a COVID infection. Timing alone doesn't prove the connection, but it's a useful detail to share with a doctor.

Genetics may play a part for some people too, though there's rarely a simple answer there either.

Usually it's more than one thing

It's tempting to look for one answer. More often several factors overlap, and none of them alone would have caused symptoms. That's roughly what the bucket theory describes, and it's also why addressing one factor can still help even if others remain.

What you can do

Start with food. A short elimination phase can show you whether food is a meaningful part of your symptoms.

Take gut symptoms seriously. If your gut is unhappy, discuss it with a clinician rather than only adjusting your diet.

Review medications with your doctor or pharmacist. Ask the question, and don't change anything on your own.

Write things down. Tracking symptoms consistently makes patterns easier to spot, including hormonal and stress patterns you'd never catch from memory.

Give it time. Progress varies a lot from person to person, and it's rarely quick. See can you cure histamine intolerance for more on what improvement tends to look like.

You don't need a complete explanation of what caused yours. Start with the factors you can actually do something about.