The Histamine Hijack: Is It Behind Your Hormones, Headaches & Hives?

19 Apr

Do you suffer from seemingly random symptoms like headaches, hives, digestive discomfort, or anxiety that come and go without explanation? You’re not alone. For many people, especially women in perimenopause and menopause, the culprit may be something called histamine intolerance (HIT). It often flies under the radar, misdiagnosed or misunderstood, because the symptoms are so wide-ranging. But there's a reason for that: histamine is involved in countless processes in the body.

What Is Histamine and Why Does It Matter?

Histamine is a naturally occurring compound with crucial roles in the body, including immune response, digestion, and regulating your sleep-wake cycle. It helps your body fight off invaders, triggers stomach acid production, and even impacts your brain chemistry. While we often associate histamine with allergies, it’s so much more than that (1, 2).

Problems begin when histamine builds up faster than your body can break it down. This overflow, often referred to as the "histamine bucket," is when symptoms start appearing—and they can vary wildly:

· Migraines or headaches

· Sinus congestion, sneezing, or post-nasal drip

· Itchy skin, hives, or hot ears

· Tinnitus (ringing in the ears)

· Fatigue and brain fog

· Bloating, diarrhoea, or constipation

· Nausea, cramps, or menstrual irregularities

· Palpitations or low blood pressure

· Sleep disruptions (especially waking at 2-3 am)

· Overthinking, anxiety, or hyperactivity

Why Do Histamine Symptoms Vary So Much?

Histamine symptoms seem so scattered because histamine receptors are found all over your body. Different receptors trigger different reactions:

H1 Receptors (skin, lungs, brain): Responsible for allergy-like symptoms such as itching, flushing, dizziness, and congestion. Blocked by antihistamines like Loratadine and Cetirizine.

H2 Receptors (stomach lining): Stimulate stomach acid production and influence heart rate. Managed with medications like Famotidine or Cimetidine.

H3 Receptors (brain): Affect sleep, appetite, and neurotransmitters. These can contribute to insomnia, anxiety, or poor focus, but current medications don’t target this receptor.

H4 Receptors (gut and immune system): Play a role in inflammation and autoimmune responses. Still being studied.

Antihistamines can help in the short term but they only block some receptors and don’t remove histamine. That's why deeper, root-cause approaches are essential (3).

Why Does Histamine Build Up?

1. Impaired DAO Enzyme Activity

DAO (diamine oxidase) is the enzyme that breaks down histamine in your gut. When DAO is low or overwhelmed, histamine can accumulate (4).

Common causes of reduced DAO include:

· Gut inflammation (e.g. IBS, leaky gut, Crohn’s)

· SIBO (Small Intestinal Bacterial Overgrowth)

· Alcohol, particularly wine

· Medications like NSAIDs, antibiotics, or antidepressants

· Genetic factors

2. Hormonal Imbalance

Oestrogen promotes histamine release and suppresses DAO. During perimenopause and menopause, fluctuating oestrogen levels can worsen or trigger HIT, even in women who’ve never had it before. Symptoms often sync up with the menstrual cycle (5).

3. Poor Gut Health

Your gut is where histamine is both produced and broken down. Any imbalance—like SIBO, candida overgrowth, or leaky gut—can disrupt this process. SIBO is a key driver, as excess bacteria produce histamine, overwhelming even normal DAO levels (6,7).

4. High-Histamine Foods

Some foods are naturally high in histamine or release it in the body. Regular consumption can overflow your histamine bucket.

Foods to watch out for:

· Aged cheeses

· Fermented foods (sauerkraut, yogurt, kombucha)

· Processed or smoked meats

· Leftovers

· Alcohol (especially red wine and beer)

· Shellfish, tuna, mackerel, and sardines

5. Nutrient Deficiencies

Vitamins and minerals like B6, C, copper, and magnesium are vital for histamine breakdown. A lack of these can slow the process (8).

6. Genetic Variants

Some people have polymorphisms in the DAO or MTHFR genes, making them more prone to histamine accumulation (8). I often run genetic testing via Lifecode Gx to assess this risk.

7. Chronic Stress

Long-term stress ramps up cortisol, weakens the gut, and triggers histamine release from mast cells. It also reduces your ability to clear histamine efficiently (9).

8. MCAS (Mast Cell Activation Syndrome)

A complex condition where mast cells release histamine inappropriately, often triggered by food, stress, heat, or exercise. MCAS and HIT often overlap (10).

9. Histamine-Releasing Foods

Some foods don’t contain histamine but still cause your body to release it:

· Citrus fruits

· Strawberries

· Tomatoes

· Chocolate

· Spinach

· Aubergine

10. Environmental Triggers

Pollen, mould, dust mites, pet dander, and chemical fragrances all contribute to your histamine load (11).

The Hormone-Histamine Connection

Oestrogen has a significant influence on how our bodies handle histamine. It not only encourages mast cells to release more histamine but also reduces the activity of DAO, the enzyme responsible for breaking histamine down. During perimenopause and menopause, oestrogen levels can swing wildly, which often worsens or even triggers histamine intolerance in women who’ve never experienced it before. As a result, symptoms like migraines, dizziness, nasal congestion, skin irritation, or flushing may suddenly appear or become more frequent, often in sync with hormonal shifts or menstrual cycles. It is a case of higher histamine levels and a lower capacity to handle it. No wonder women in perimenopause and menopause often find themselves suddenly sensitive to wine, chocolate, or cheese—all classic high-histamine triggers (5).

Gut Health: The Epicentre of Histamine Balance

Your gut microbiome influences how much histamine you produce and how well you break it down. SIBO, candida, and other imbalances contribute to histamine issues.

Low stomach acid, often wrongly treated with acid blockers, can actually lead to bacterial overgrowth (see my blog – a Rethink on Reflux). Supporting digestion with digestive enzymes and HCl supplements (with professional guidance) can be game changers. (6,7).

Not All Probiotics Are Your Friend

Some probiotic strains produce histamine. These include:

· Lactobacillus reuteri

· Streptococcus thermophilus

· Lactobacillus casei

· Certain E. coli strains

If you're histamine-sensitive, and taking a probiotic, opt for strains like Bifidobacterium infantis or Lactobacillus plantarum, which are less likely to cause issues.

Candida and Fungal Overgrowth

Candida is a normal gut resident, but overgrowths can trigger immune reactions and histamine release. This adds to your overall histamine burden. Antibiotics, stress, and sugar-heavy diets can tip the balance.

Is Your IBS Really Histamine Intolerance?

Research shows that 58% of IBS patients react to histamine-releasing foods. These individuals also have more mast cells throughout the gut. In some cases, a low-FODMAP diet reduces both histamine levels and IBS symptoms significantly (14).

Managing Histamine Intolerance: Where to Start

Diet

Everyone responds to histamine differently, and that’s why a personalised approach can make all the difference. Together, we can explore your unique triggers and create practical strategies that work for you. A great starting point is focusing on fresh, unprocessed foods. While avoiding leftovers and limiting fermented, aged, or preserved items often helps, many people need a more targeted, gentle protocol to truly feel better—and that’s exactly where I can support you. If you're feeling overwhelmed or unsure where to begin, I’m here to help you every step of the way.

Supplements

A variety of natural supplementation has been shown to support lowering histamine or alleviating the symptoms whilst we address the underlying causes.

· Vitamin C: Natural antihistamine and immune supporter (14).

· Quercetin: Stabilises mast cells, reducing histamine release (15).

· DAO Enzyme: Supports dietary histamine breakdown (4).

· Magnesium: Calms nervous system and supports enzyme function (16).

Lifestyle Shifts

· Reduce stress with yoga, meditation, or breathwork

· Get enough sleep to balance immune and hormonal health

· Exercise moderately to support lymph flow and detoxification

Final thoughts

Histamine intolerance is real, complex, and often overlooked—especially in midlife women. If your symptoms feel like they’re coming from everywhere and nowhere at once, histamine could be the common thread.

By identifying triggers, supporting your gut and hormones, and making simple diet and lifestyle shifts, you can take back control and feel like yourself again.

Need more support? Contact me to book in for a consultation or functional testing that may help us uncover the causes to your histamine issues and find the support you need to regain histamine tolerance.

Academic references:

emma davies