Histamine Intolerance: What You Need to Know

Medically Reviewed By Elizabeth Feuille, MD
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The term “histamine intolerance” refers to the body’s inability to break down histamine. While the term became more popular in recent years, there is not enough scientific evidence to make it a clinical diagnosis. High histamine levels can cause bloating, stomach pain, dizziness, and a rapid heart rate. Treatment for histamine intolerance may include medications or a low histamine diet.

Read on to learn more about the causes, symptoms, and treatments for histamine intolerance.

What is histamine?

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Histamine is a chemical called a biogenic amine. Basophils and mast cells mainly produce and store it. They are white blood cells involved in your body’s response to allergens.

When an allergen enters your body or comes into contact with your skin, your immune system sends out signals to release histamine. Histamine widens your blood vessels, allowing other substances in your body to travel to the area affected by the allergen. These substances then repair your tissues.

What are the causes of histamine intolerance?

Although experts need more research to prove it, histamine intolerance may result from the body’s inability to break down histamine. Usually, an enzyme called diamine oxidase (DAO) breaks down histamine.

When someone has a DAO deficiency, histamine does not break down, building up in their system. An excess of histamine can come from foods that contain histamine or trigger its release in the body.

DAO deficiency can result from a genetic mutation, or it may be an acquired condition. Certain disorders — such as gastrointestinal and inflammatory bowel diseases — may cause DAO function impairment resulting in histamine intolerance symptoms.

A DAO deficiency can be reversible if it results from factors like alcohol or certain medications. Medications that can cause impaired DAO function include chloroquine, cimetidine, and veramapil.

What are the symptoms of histamine intolerance?

Histamine intolerance can cause symptoms in many areas of the body.

Respiratory symptoms

Respiratory symptoms resulting from histamine intolerance may include:

Gastrointestinal symptoms

Histamine intolerance can trigger many gastrointestinal symptoms, including:

Skin symptoms

Skin symptoms may include:

Other symptoms

Histamine intolerance can cause other symptoms as well, including rapid heart rate, headaches, dizziness, weakness, or spells of fainting.

Related conditions that cause similar symptoms

The symptoms of histamine intolerance can be very similar to other conditions, such as food allergies and scromboid fish poisoning.

Scromboid fish poisoning occurs after an individual eats certain kinds of spoiled fish and can cause many of the same symptoms as histamine intolerance. Certain fish species contain high levels of histidine, which bacteria can convert to histamine. These levels are high enough to cause symptoms in almost anyone.

The difference between scromboid fish poisoning and suspected histamine intolerance is that scromboid fish poisoning does not result from an enzyme deficiency or a specific intolerance.

How do doctors diagnose histamine intolerance?

Because histamine intolerance is not a clinically-recognized condition, it does not have its own diagnostic criteria.

If you are experiencing symptoms of suspected histamine intolerance, doctors will typically try to eliminate other conditions.

The symptoms of histamine intolerance can be similar to food allergy symptoms. Therefore, doctors may recommend trying an elimination diet. An elimination diet involves cutting out foods that commonly trigger allergic reactions, such as dairy, shellfish, and peanuts.

Your doctors may also have you follow a low histamine diet to see if your symptoms improve.

What are the treatments for histamine intolerance?

Treatment for histamine intolerance may include a low histamine diet and medications.

Low histamine diet

People with suspected histamine intolerance may benefit from a low histamine diet. Certain foods and drinks contain high levels of histamine, including:

  • shellfish
  • eggs
  • foods that are fermented
  • avocados
  • bananas
  • aged cheese
  • spinach
  • citrus
  • meats and fish that are smoked or processed
  • alcohol

It is important to note that some foods — such as mushrooms, soybeans, or nuts — do not contain high levels of histamine but may trigger histamine release in the body, causing symptoms.

Foods that are low in histamine include:

  • fresh meat and fish
  • noncitrus fruits
  • dairy substitutes
  • gluten-free grains

Although experts need more research, a 2020 research review suggested that a low histamine diet can result in a reduction in the presence and severity of histamine intolerance symptoms.


Some people with suspected histamine intolerance may benefit from antihistamines, which are drugs that block the effects or production of histamine. While antihistamines typically come in tablet form, they may also be available as liquids, lotions, nasal sprays, or eye drops.

Some researchers also proposed that DAO supplementation can help alleviate histamine intolerance symptoms and potentially allow for a less restrictive diet, but experts need more research on this topic, too.

If you take a medication that can cause a DAO deficiency, you may need to stop taking the medication and find an alternative.

What is the outlook for people with histamine intolerance?

With treatment, the outlook for people with histamine intolerance is generally good. It is important to get treatment because people who have histamine intolerance along with allergies can experience a dangerous buildup of histamine in their systems. This buildup can trigger serious symptoms such as asthma attacks or anaphylactic shock.

Frequently asked questions

These are a few commonly asked questions about histamine intolerance. Dr. Elizabeth Feuille reviewed the answers.

Can histamine intolerance be cured?

Histamine intolerance is not definitively curable because experts cannot provide a clinical diagnosis yet.

However, if alcohol or a certain drug causes symptoms of histamine intolerance, eliminating those things may provide relief. Avoiding foods containing histamine, triggering histamine release, or interfering with histamine breakdown may also be beneficial.

Is histamine tolerance the same as allergies?

Histamine intolerance is not the same as allergies. With allergies, exposure to an allergen causes your immune system to release allergic proteins, including histamine.

In contrast, histamine intolerance symptoms may arise from an excess amount of histamine in your system that your body cannot break down. These symptoms often manifest after you consume certain foods or drinks, but this results from their histamine content and not an immune response to the foods or drinks themselves.


Histamine intolerance is a syndrome that may occur when your body cannot break down histamine, leading to a buildup of the chemical in your body. A deficiency of DAO, an enzyme that breaks down histamine, might cause histamine intolerance.

Common symptoms of histamine intolerance include bloating, increasing heart rate, flushing, itching, and breathing difficuulties. Doctors may recommend an elimination or low histamine diet to narrow down the cause of your symptoms.

Antihistamines may help alleviate symptoms. While DAO supplements are available, their benefits in suspected histamine intolerance require more study.

Talk with your doctor if you are experiencing symptoms consistent with histamine intolerance.

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Medical Reviewer: Elizabeth Feuille, MD
Last Review Date: 2022 Jun 11
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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