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Histamine intolerance is a complex reaction to the chemical histamine that can lead to a variety of symptoms. Here’s what you need to know about histamine intolerance and how it may affect you.

What Is Histamine?

Histamine is a naturally occurring chemical found in the cells of the body. It plays a role in regulating your sleep cycle and supporting brain function. It also helps your body fight off infections, though doing so produces allergy symptoms like sneezing and a runny nose.

What Is Histamine Intolerance?

Histamine intolerance is a condition in which your body doesn’t break down histamine in foods. The histamine then builds up and causes symptoms like diarrhea, shortness of breath, and headaches.

Some scientists believe that histamine intolerance affects up to 1% to 3% of the population. It seems to affect middle-aged people more than younger people.

However, histamine intolerance remains controversial. The American Academy of Allergy, Asthma & Immunology doesn’t recognize histamine intolerance as a condition. One recent study concluded that histamine intolerance wasn’t to blame in most people who thought it caused their symptoms.

Is Histamine Intolerance a Food Allergy?

No, histamine intolerance is not the same as a food allergy. It may result in many of the same symptoms as a food allergy, but the causes are different.

Food allergies are an immune system reaction to food that the immune system mistakenly identifies as harmful. This sets off a series of events in which cells release histamine and other chemicals into the bloodstream. Too much histamine causes nausea, hives, itchy eyes, wheezing, and sneezing.

Histamine intolerance happens when the digestive system can’t break down histamines in the body, leading to too much histamine in your system. It may happen because of a gut condition or lack of diamine oxidase (DAO). DAO is the protein that breaks down histamine in your body.

Triggers for histamine intolerance include aged or fermented foods, such as wine, beer, sauerkraut, and cheese. You may also react when you let foods — especially meats — sit out too long. Canned and processed foods may also trigger histamine intolerance.

What Are the Signs of Histamine Intolerance?

Symptoms of histamine intolerance vary from person to person. They may include:

• Abdominal pain.
• Diarrhea.
• Flushing.
• Headaches.
• Insomnia.
• Irregular or racing heartbeat.
• Itching.
• Nausea.
• Rashes.
• Runny or stuffy nose.
• Swelling.
• Vomiting.
• Watery eyes.

Many people believe they experience a “histamine dump.” This phenomenon usually happens at night when your body releases a sudden surge of histamine. A histamine dump can interrupt your sleep and cause headaches, flushing, itching, anxiety, and a racing heart.

Is Histamine Intolerance Linked to ADHD?

Some researchers believe that histamine intolerance may have a link to attention deficit hyperactivity disorder (ADHD). Some symptoms — insomnia, restlessness, and distractibility — are similar.

An accumulation of histamine may contribute to ADHD symptoms. However, scientists need to do more research before they can say there’s a definite link between histamine intolerance and ADHD.

What Are the Treatments for Histamine Intolerance?

Seeing a doctor is important if you suspect you have histamine intolerance.

There’s no specific test for histamine intolerance. Instead, your doctor will ask about your medical history and symptoms. They can run tests to rule out other causes of your symptoms, such as food allergies, irritable bowel syndrome, or asthma.

Symptoms of histamine intolerance can affect multiple organs, which makes diagnosis difficult. Your tolerance to foods can also change over time.

Your doctor may prescribe an antihistamine to help control your symptoms. Antihistamines don’t cure histamine intolerance, but they can help reduce its symptoms.

How Can Diet Help?

There’s no such thing as a histamine-free diet, but certain foods are higher in histamine than others. Exposure to histamines can also occur beyond diet, but sometimes, making simple changes in the foods you eat can help calm your symptoms.

If your doctor suspects histamine intolerance, they may refer you to a registered dietitian. This specialist can advise you on what to eat and what not to eat.

Your dietitian may suggest that you:

• Cut out certain foods — One simple way to test for histamine intolerance is to avoid a specific item for two to four weeks. If your symptoms improve, you may want to avoid that food or drink in the future.
• Eat Fresh food as much as possible — to limit histamine exposure.
• Keep a food diary — You’ll write down everything you eat, such as if you notice symptoms and when they occur. Symptoms of histamine intolerance generally occur about 30 minutes after eating.

High-histamine foods

The following foods are high in histamine.

• Avocados.
• Bananas.
• Beer, wine, and champagne.
• Cheese, especially blue cheese, Parmesan, Camembert, Gouda, cheddar, and other hard cheeses.
• Chocolate and cocoa.
• Coffee.
• Cured and processed meats such as sausage, ham, pepperoni, salami, and bacon.
• Eggplant.
• Fava beans.
• Fermented soy products such as miso and tempeh.
• Fermented or smoked fish
• Oranges.
• Peanuts.
• Pineapples.
• Plums.
• Sauerkraut.
• Spinach.
• Strawberries.
• Tangerines.
• Tomatoes.

There are many conditions that have symptoms that might make you think you have histamine intolerance. Before following this diet, be sure to talk to your doctor about your medical history and symptoms.

Editor's Note: This article was originally published on February 11, 2025, and was last reviewed on January 12, 2026.