What Is Histamine Intolerance?

Michael Eisenwasser 4 min read

Histamine intolerance happens when your body has trouble breaking down histamine efficiently. It's not a food allergy in the classic sense. Instead, it's an imbalance: more histamine coming in (or being released) than your body can handle.

This can cause symptoms across multiple systems: digestion, skin, sleep, mood, and your nervous system. I've lived with histamine intolerance for most of my life, dealing with insomnia, recurring body pain, and anxiety before I finally understood what was going on.

If you've been struggling with unexplained symptoms and feeling like you're the only one, you're not. Histamine intolerance is often under-recognized and frequently overlaps with mast cell activation syndrome (MCAS) and other food sensitivities.

See Histamine Intolerance vs MCAS for a deeper comparison.

What Is Histamine?

Histamine is a naturally occurring compound your body produces. It does several important things:

• Regulates stomach acid for digestion
• Acts as a neurotransmitter in the brain
• Supports immune responses
• Helps control blood vessel dilation and blood pressure

Histamine is also found in many foods, particularly those that are aged, fermented, processed, or stored for a while. How food is handled and stored often matters as much as what the food is, which is why freshness plays such a big role in symptoms.

See Why Freshness Matters More Than Food Lists.

Normally, enzymes like diamine oxidase (DAO) break down dietary histamine before it causes problems. When this process is impaired (from genetics, gut health issues, medications, or cumulative triggers), histamine builds up.

Histamine Intolerance and MCAS

Histamine intolerance and MCAS often get discussed together because both involve histamine-related symptoms.

With histamine intolerance, the issue is mostly reduced breakdown of histamine.

With MCAS, mast cells release excessive amounts of histamine and other inflammatory mediators.

The underlying mechanisms differ, but the outward symptoms can look very similar. This overlap is why many people explore both possibilities while tracking their experiences.

Common Symptoms

When histamine accumulates faster than your body can clear it, you might experience:

• Headaches or migraines
• Skin flushing, itching, or hives
• Nasal congestion or runny nose
• Digestive discomfort (bloating, diarrhea, stomach pain)
• Fatigue or low energy
• Anxiety, irritability, or feeling overstimulated
• Heart palpitations
• Trouble falling or staying asleep

Symptoms can appear within minutes or take hours to develop, which makes histamine intolerance hard to identify without consistent tracking.

See Common Symptoms of Histamine Intolerance for a fuller breakdown.

Gluten, Dairy, and Histamine

Many people with histamine intolerance notice sensitivity to gluten, dairy, or both, even without a formal allergy or celiac disease.

This doesn't necessarily mean gluten or dairy are high in histamine. Often it reflects a coexisting issue (celiac disease, non-celiac gluten sensitivity, lactose intolerance, or milk protein sensitivity) or gut inflammation that can lower overall tolerance.

Note that aged cheeses can be high in histamine, while fresh dairy often is not. Reactions can be delayed and inconsistent, which makes it hard to tell which foods are actually causing problems.

See Is Gluten High in Histamine? and Is Dairy High in Histamine? for more detail.

Why Tracking Matters

There's no single test that definitively diagnoses histamine intolerance. For this reason, pattern recognition over time is one of the most practical tools available.

Tracking helps you:

• Find foods that consistently precede symptoms
• Notice delayed reactions (hours or even the next day)
• Understand how stress, sleep, alcohol, and other factors affect your tolerance
• Avoid cutting out foods unnecessarily

The Histamine Tracker app is built for exactly this. It makes logging quick, then uses AI to analyze your data and surface patterns you'd miss on your own. See How to Track Histamine Symptoms Effectively for more on how tracking works.

What You Can Do

Managing histamine intolerance usually involves:

• Paying attention to food freshness, not just food type
• Tracking food and symptoms to find your personal triggers
• Doing an elimination and reintroduction process to identify what you react to
• Reducing overall histamine load when symptoms flare
• Working with a healthcare provider if symptoms are severe or persistent

Food lists that show which foods are high, medium, or low histamine can be a helpful starting point. Keep in mind that histamine content varies by storage, brand, ripeness, and preparation, so use lists alongside freshness awareness and personal tracking.

Understanding histamine intolerance is the first step toward making it more manageable.

Track your symptoms and discover patterns with Histamine Tracker. Includes a database of 1,000+ foods with histamine ratings.