Histamine intolerance is an inability to break down histamine in your body, causing it to build up. Certain foods that are high in histamine or that cause your body to release histamine can give you an upset stomach, headache or allergy symptoms. Common trigger foods include fish, alcohol and fermented or aged foods.
Histamine intolerance (HIT) is a condition where histamine builds up in your body. Histamine is a chemical that your body naturally makes and that’s present in some foods. Some experts think that if your body can’t break histamine down like it’s supposed to, it can build up and give you an upset stomach, headache or allergy symptoms.
This is different from histamine intoxication (also called histamine poisoning). Histamine intoxication usually happens as a food poisoning outbreak, affecting many people who ate the same high-histamine meal. Public health officials usually trace it back to certain types of fish.
Histamine intoxication is well-documented. But histamine intolerance is more controversial. Experts disagree about whether relatively low levels of histamine could cause symptoms, or if it’s more likely that irritable bowel syndrome or another condition causes symptoms that look like HIT.
No, histamine intolerance isn’t an allergy, even though it has some symptoms of allergic reactions. It’s sometimes called a “pseudoallergy,” as it looks similar to an allergy but has a different cause.
The American Academy of Allergy and Immunology doesn’t currently recognize histamine intolerance as a condition. It’s a controversial issue.
Some experts suggest that if your body can’t break down histamine as well as it should, it can build up in your body and cause symptoms. But a 2023 study ruled out histamine intolerance in most people who thought it was causing their symptoms. The study’s authors and other experts suggest that other conditions cause symptoms that look like a histamine reaction.
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The symptoms of histamine intolerance are different from person to person. You may have one or more of these symptoms:
According to some theories, histamine intolerance symptoms could happen when your body can’t break down histamine. Histamine is a chemical signal that opens up your blood vessels, constricts your airways and gastrointestinal (GI) tract, and creates mucus. Mast cells in your mucous membranes release histamine and other chemical signals to help fight infections and regulate your organs.
Your body uses enzymes, mostly diamine oxidase (DAO), to break down histamine. If you have low levels of DAO and you eat something or take medication that increases your level of histamine, the histamine signals could cause symptoms like diarrhea, headaches, runny nose and hives.
Experts aren’t really sure what would cause some people to have low levels of DAO or an inability to break down histamine as they should. Some factors that might contribute include:
Some foods contain large amounts of histamine. These include foods that involve an aging or fermentation process like wine, beer and cheeses. Other foods can cause your mast cells to release histamine (histamine liberators). Both of these types of foods can cause excess amounts of histamine in your body.
Some examples include:
Certain medications can increase the amount of histamine in your body. They do this by either causing your mast cells to release histamine or reducing the amount of DAO that’s breaking down histamine in your body. They include:
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There aren’t any proven ways to diagnose histamine intolerance, and not all providers recognize HIT as an official diagnosis. A provider can listen to your symptoms and try to diagnose you based on whether eliminating certain foods makes you feel better. Your provider might also perform various tests or procedures to help make a diagnosis. These include:
Treatment usually involves avoiding foods or beverages that cause your symptoms. To test what you can safely eat, you stop eating any possible triggers for a few weeks. If you haven’t had symptoms in that time, you start adding them back in one by one. If you start having a reaction to certain foods or combinations of foods but not others, you can avoid only the ones that make you react.
A provider may recommend medications that might help relieve symptoms of histamine intolerance, in combination with diet changes. They may suggest:
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People with food sensitivities can usually manage their condition by changing their diet. In severe cases, taking DAO supplements or other medications can help. Sometimes the intolerance is temporary, and you can eventually go back to eating foods that you’d been avoiding.
Talk to your healthcare provider if you have unexplained symptoms or you think you have a food intolerance. They can help you sort out whether it’s an allergy, intolerance or something else.
Go to the emergency room or call 911 if you have signs of anaphylaxis, including:
It might be helpful to ask your healthcare provider:
Food sensitivities can seem mysterious at first. Your symptoms might be vague or inconsistent, and you might not be able to connect them to any one trigger. It might take some detective work to figure out what makes you sick and how to avoid it. But by working together with a healthcare provider, most people can manage their symptoms with diet or medication changes.
Last reviewed on 08/27/2024.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy