Have you ever felt flushed, itchy, anxious, or bloated for no obvious reason? Maybe you experience sudden headaches, brain fog, or digestive issues that come and go. While many people think of histamine only in relation to hay fever or allergies, high histamine levels in the body can cause a wide range of symptoms that affect daily life – from gut health to hormones, energy, and mood.

What is Histamine?

Histamine is a natural chemical produced by your immune system. It plays an important role in:

Fighting infections
Regulating stomach acid for digestion
Acting as a neurotransmitter in your brain

However, when histamine builds up in your body faster than it can be broken down, it can lead to a condition called histamine intolerance or high histamine.

Symptoms of High Histamine

If your body struggles to clear excess histamine, you might experience:

Headaches or migraines
Nasal congestion or sinus issues
Itchy skin, rashes, or hives
Flushing or feeling hot after meals
Heart palpitations or anxiety
Digestive problems like bloating, diarrhoea, or reflux
Low blood pressure or dizziness
Trouble sleeping or feeling wired but tired
Worsening of PMS symptoms
Worsening hay fever or asthma symptoms

These symptoms often seem unrelated at first. You might go to your GP for reflux, later for skin issues, and later for anxiety, never realising they all connect back to histamine.

How Does Histamine Get High?

There are several reasons why histamine can build up in the body:

Eating High-Histamine Foods

Some foods naturally contain high histamine or trigger histamine release, such as:

Aged cheeses
Processed meats (salami, ham, bacon)
Fermented foods (sauerkraut, kombucha, vinegar)
Alcohol, especially wine and beer
Canned or leftover foods
Tomatoes, spinach, eggplant, avocado

For many people, these foods are healthy choices, but if your body struggles to break down histamine, they can cause symptoms.

Poor Breakdown of Histamine (Low DAO Enzyme)

The main enzyme that breaks down histamine in your gut is called DAO (diamine oxidase). Some people have low DAO activity due to genetics, gut damage, medications, or nutrient deficiencies. This means histamine from food and bacteria builds up and causes problems.

Gut Health Issues

If you have gut inflammation, SIBO (small intestinal bacterial overgrowth), or leaky gut, your body’s ability to clear histamine decreases. Some gut bacteria also produce histamine, adding to the load. Many people with bloating, reflux, or IBS-like symptoms find histamine intolerance plays a role in their gut issues.

Hormonal Changes

Histamine is closely linked with oestrogen. For some women, histamine symptoms worsen around ovulation or just before their period when oestrogen peaks. If you struggle with PMS, painful periods, or perimenopausal symptoms alongside histamine symptoms, this connection could be significant for you.

Stress

Stress impacts your ability to clear histamine. It increases inflammation in the gut, alters your microbiome, and changes how your immune system responds. Many people notice their histamine symptoms flare during busy or stressful weeks.

Medications

Some common medications block DAO activity, including certain painkillers (NSAIDs like ibuprofen), antidepressants, and antihistamines themselves. If you’re on regular medication and experiencing symptoms, it’s worth discussing options with your health practitioner.

Why Does This Matter for You?

If you’re someone who:

Feels anxious, flushed, or gets palpitations after meals
Experiences rashes, eczema, or unexplained skin issues
Struggles with bloating, reflux, or IBS-like symptoms
Gets worse hay fever symptoms despite antihistamines
Feels tired but wired, with trouble sleeping
Notices symptoms worsen around your period

… then high histamine could be part of your health puzzle.

Often, clients come to me feeling frustrated. They’ve been told their blood tests are normal, their allergies are “just allergies,” or they’ve been prescribed reflux medication without addressing underlying causes. Living with these symptoms daily can reduce your quality of life, focus, and confidence.

How Can You Reduce High Histamine Symptoms?

As a naturopath, my approach is to support your body’s ability to clear histamine, reduce inflammation, and heal your gut. Some general strategies include:

Eating Fresh Foods: Reduce leftovers and processed foods that increase histamine.
Identify Trigger Foods: Keep a food and symptom diary to notice patterns.
Support Gut Health: Heal the gut lining and balance the microbiome to reduce histamine production.
Increase DAO Activity: Nutrients like vitamin C, copper, B6, and zinc help DAO function. Specific DAO supplements may be used under guidance.
Reduce Stress: Breathing exercises, gentle movement, and good sleep all help lower inflammation and histamine.
Consider Hormonal Balance: If symptoms worsen with your cycle, supporting oestrogen detoxification may be key.

It’s important to remember that everyone’s histamine tolerance is different. Some people only react when under stress or hormonal changes, while others are highly sensitive to small amounts.

Final Thoughts

If you suspect high histamine is affecting your health, don’t ignore your symptoms. Working with a qualified practitioner can help you identify triggers, support your body’s natural detoxification, and restore balance so you can feel calm, clear-headed, and comfortable in your own body again.

References

Maintz, L., & Novak, N. (2007). Histamine and histamine intolerance. The American Journal of Clinical Nutrition, 85(5), 1185-1196. https://doi.org/10.1093/ajcn/85.5.1185
Smolinska, S., & Jutel, M. (2021). Histamine, histamine receptors, and their role in immune pathology. International Reviews of Immunology, 40(5), 347-360. https://doi.org/10.1080/08830185.2020.1823927
Schwelberger, H. G. (2010). Histamine intolerance: A metabolic disease? Inflamm Res, 59(Suppl 2), S219–S221. https://doi.org/10.1007/s00011-010-0217-x
Reese, I., Ballmer-Weber, B., Beyer, K., et al. (2017). German guideline for the management of adverse reactions to ingested histamine. Allergo Journal International, 26(2), 72–79. https://doi.org/10.1007/s40629-017-0011-5
Pinzer, T. C., Tietz, E., & Schink, M. (2018). Low-histamine diet improves symptoms in patients with histamine intolerance. Deutsches Ärzteblatt International, 115(27-28), 458–464. https://doi.org/10.3238/arztebl.2018.0458
Comas-Basté, O., Sánchez-Pérez, S., Veciana-Nogués, M. T., et al. (2020). Histamine intolerance: The current state of the art. Biomolecules, 10(8), 1181. https://doi.org/10.3390/biom10081181

Is Histamine Making You Feel Unwell? The Hidden Signs of High Histamine