Histamine Intolerance and Heart Palpitations Explained

Histamine intolerance and heart palpitations are linked more often than many people expect. A pounding, racing or fluttering heartbeat after a meal can be frightening, especially when it arrives with flushing, a headache or a blocked nose. Histamine does act on the heart and blood vessels, and a fast heartbeat is listed among the possible symptoms of histamine intolerance in the medical literature. But palpitations have many causes, and some of them need prompt medical attention. This guide explains how histamine affects the heart, what a histamine-related pattern tends to look like, which other causes doctors check for, and what you can do with your doctor to work out what is going on.

The most important message comes first. Palpitations should always be checked by a doctor before you put them down to food. Once heart and other causes have been ruled out, a structured low histamine diet and a careful symptom diary can show whether histamine plays a part.

What heart palpitations feel like

Palpitations are a sudden awareness of your own heartbeat. People describe them in many ways: a racing heart, a pounding in the chest or neck, a fluttering, a feeling that the heart has skipped a beat, or a heavy thump followed by a pause. They can last a few seconds or several minutes. Many palpitations are harmless, but they can also be a sign of a heart rhythm problem or another medical condition.

The NHS guide to heart palpitations lists common triggers such as strenuous exercise, poor sleep, stress and anxiety, alcohol, caffeine and nicotine, some medicines, and hormonal changes in pregnancy or the menopause. It also lists conditions such as iron deficiency anaemia, an overactive thyroid, heart rhythm problems and heart valve disease. Histamine is not on that list, which is a useful reminder that the common causes should be checked first.

How histamine affects the heart and blood vessels

Histamine works by attaching to four types of receptors, called H1, H2, H3 and H4. Two of these are important for the heart and circulation. Our guides to the H1 receptor and the H2 receptor explain them in more detail.

• Blood vessels widen. Through H1 and H2 receptors, histamine relaxes the walls of small blood vessels. This causes flushing and warmth, and it can lower blood pressure. When blood pressure drops, the body responds by making the heart beat faster to keep blood flowing to the brain and organs.
• The heart beats faster and more forcefully. H2 receptors are present in heart tissue. In laboratory and human studies, stimulating them increases heart rate and the force of each beat, which some people feel as pounding.
• Rhythm changes. In larger amounts, histamine has been linked with disturbances of heart rhythm. This is mainly described in allergic reactions and in scombroid fish poisoning, where people eat spoiled fish containing very high levels of histamine.

A widely cited review of histamine intolerance in The American Journal of Clinical Nutrition lists a fast heartbeat (tachycardia), irregular heartbeat and low blood pressure among the symptoms reported in histamine intolerance, alongside flushing, headache, a blocked or runny nose and digestive symptoms. These cardiovascular symptoms are usually described as part of a wider pattern rather than on their own.

What a histamine-related pattern can look like

There is no test that proves palpitations are caused by histamine. What people and their doctors look for is a pattern over time. Features that may point towards histamine include:

• Palpitations that tend to follow meals, often within an hour or so, rather than appearing at random.
• Other histamine-type symptoms at the same time, such as flushing of the face and neck, a headache, a blocked or runny nose, itching or hives, or bloating and diarrhoea.
• A link with particular foods and drinks that are high in histamine or commonly reported as triggers, such as wine, beer, aged cheese, cured meats, leftovers and fermented foods. Our list of high histamine foods to avoid covers the main ones.
• Symptoms that ease when the diet is simpler and fresher, and return when high histamine foods are reintroduced.
• A tendency to be worse on days when other things add to the histamine load, such as pollen season, infections, alcohol or the days before a period.

None of these features rules out another cause. A person can have histamine intolerance and also have a heart rhythm problem, anaemia or a thyroid condition. That is why testing comes before diet changes, not after.

Why alcohol is such a common trigger

Alcohol is one of the most frequently reported triggers for palpitations in general, and it causes trouble in histamine intolerance in several ways. Many drinks, particularly red wine and some beers, contain histamine and other amines. Alcohol and its breakdown product acetaldehyde are thought to interfere with histamine breakdown. Alcohol also widens blood vessels and can directly affect heart rhythm, especially when drunk in larger amounts. Heavy drinking sessions are a recognised trigger for atrial fibrillation, an irregular heart rhythm that needs medical treatment.

If your palpitations tend to follow alcohol, taking a break from drinking is a sensible step, and it makes any diary easier to interpret. If you do drink, our guide to the lowest histamine alcohol drinks and our article on histamine and wine explain which options tend to be better tolerated.

Other causes doctors check first

Because palpitations can be a sign of a heart condition, a doctor will usually want to examine you and arrange some simple tests before considering histamine. Common checks include:

Your doctor may also ask about caffeine, energy drinks, nicotine, recreational drugs, sleep, anxiety and family history of heart problems. Depending on the findings, they may refer you to a cardiologist.

Palpitations, anxiety and the histamine cycle

Palpitations and anxiety often feed each other. A sudden racing heart is frightening, the fear releases adrenaline, and adrenaline makes the heart beat faster still. Anxiety on its own can cause palpitations, and it can also make people more aware of normal changes in their heartbeat. This does not mean the palpitations are imagined. It means that calming the fear response can help, whatever the original trigger. Our guide to histamine intolerance and anxiety looks at this overlap in more detail.

Simple steps that many people find useful during an episode include sitting down, breathing slowly with a longer out-breath than in-breath, sipping water and reminding yourself that you have a plan agreed with your doctor. If you have been told your heart is healthy, knowing that can take a lot of the fear away.

Postural tachycardia and mast cell conditions

Some people with histamine-type symptoms have a large rise in heart rate when they stand up, along with dizziness, tiredness and brain fog. This can be a sign of postural orthostatic tachycardia syndrome (POTS). POTS is diagnosed by measuring heart rate and blood pressure lying and standing, and it is managed by doctors with advice on fluids, salt, compression garments, exercise and sometimes medicines. POTS, hypermobile Ehlers-Danlos syndrome and mast cell activation syndrome are sometimes seen together, as our article on hEDS, POTS and MCAS explains.

If flushing, hives, wheezing or fainting episodes happen without a clear food link, or if you react to many different triggers such as heat, exercise or stress, your doctor may consider a mast cell condition. Our guide to mast cell activation syndrome covers the symptoms and tests. Dizziness is covered separately in our article on histamine intolerance and dizziness.

What may help once heart causes are ruled out

When tests are normal and your doctor agrees histamine may be involved, the approach is the same as for histamine intolerance in general.

• A short, structured low histamine diet. Reducing high histamine foods for a few weeks, then reintroducing them one at a time, is the main way to find out whether food is driving your symptoms. Our beginner’s guide to the low histamine diet explains how to do this without cutting out more than you need to.
• Freshness. Histamine builds up in protein foods as they age. Cook fresh meat and fish soon after buying, freeze leftovers in portions on the day you cook them, and reheat only once, until steaming hot throughout (74°C).
• Cutting back on stimulants. Caffeine from coffee, tea, energy drinks and chocolate can cause palpitations on its own. Reducing it during the trial period removes one possible trigger. See histamine intolerance and coffee.
• Alcohol. As described above, taking a break makes a big difference for many people.
• Regular meals and fluids. Large meals, dehydration and low blood sugar can all trigger a fast heartbeat. Smaller, regular meals and enough fluid help.
• Sleep and stress. Poor sleep and stress lower many people’s threshold for symptoms of all kinds.

Some people also discuss treatments with their doctor, such as antihistamine medicines or a DAO enzyme supplement taken with meals. These should be agreed with a doctor or pharmacist, who can check they are suitable alongside any other medicines you take. We do not give doses, because the right choice depends on your health, test results and other medicines.

Medicines, supplements and the heart

Several medicines are relevant to palpitations and histamine at the same time.

• Medicines that may affect DAO. Some heart and blood pressure medicines, antibiotics, antidepressants and painkillers appear on lists of drugs that may reduce DAO activity, mostly based on laboratory data. Our guide to medications that may block DAO explains the evidence. Never stop or change a heart medicine, or any prescribed medicine, without talking to your doctor. Stopping some heart medicines suddenly can be dangerous.
• Decongestants. Tablets and sprays containing pseudoephedrine, phenylephrine or similar ingredients can raise heart rate and blood pressure. People with histamine-type nasal symptoms sometimes use them often without realising the effect.
• Some older antihistamines. First generation antihistamines can occasionally cause a fast heartbeat as a side effect. Our guide to antihistamine generations explains the differences.
• Supplements and herbal products. Products containing stimulants, high doses of caffeine or certain herbal extracts can trigger palpitations. Tell your doctor about everything you take, including products bought online.

Keeping a palpitation diary

A simple diary is one of the most useful things you can bring to your doctor. It helps them decide which tests are needed and helps you see whether food plays a part. For each episode, note:

1. The date, time and how long it lasted.
2. What it felt like, such as racing, pounding, fluttering or skipping.
3. Your pulse, if you can measure it, and whether it felt regular or irregular. Many smartwatches and phones can record a heart rhythm strip that your doctor can look at.
4. What you had eaten and drunk in the previous few hours, including alcohol and caffeine.
5. Any other symptoms, such as flushing, headache, dizziness, a blocked nose or digestive upset.
6. Other factors such as stress, poor sleep, exercise, illness or the stage of your menstrual cycle.

Our histamine food diary can help you keep track. After a few weeks, patterns are often much clearer than they feel day to day.

Hormones, pregnancy and the menopause

Hormonal changes are a common, often overlooked cause of palpitations. Many women notice a faster or more noticeable heartbeat in the days before a period, during pregnancy and around the menopause. Estrogen and histamine influence each other, and some women with histamine intolerance find that their food reactions also change across the menstrual cycle. Our guides to histamine and the menstrual cycle and perimenopause and histamine intolerance explain this link.

In pregnancy, the heart naturally beats faster and blood volume rises, so mild palpitations are common. DAO levels also rise sharply because the placenta produces the enzyme, and some women find their histamine symptoms ease. Report new or worsening palpitations in pregnancy to your midwife or doctor. Call emergency services if they come with chest pain, breathlessness or fainting. Our article on histamine intolerance in pregnancy covers what changes and what stays the same.

Noting your cycle in your diary makes these patterns easier to spot, and it gives your doctor useful information.

When to see a doctor

Call emergency services straight away if you or someone else has swelling of the lips, tongue or throat, difficulty breathing or wheezing, a hoarse voice, feeling faint or collapse. These are signs of anaphylaxis, which needs an adrenaline (epinephrine) injection and urgent care.

Call emergency services or go to an emergency department if palpitations do not go away, or come with chest pain, shortness of breath, fainting or feeling as though you are about to faint. Do not drive yourself.

See your doctor soon if palpitations keep coming back, are becoming more frequent, last longer than a few minutes, or if you have a heart condition or a family history of heart problems or sudden death at a young age. Also see your doctor if you are pregnant and notice new palpitations. Talk to your doctor before starting any supplement if you take heart, blood pressure or blood thinning medicines, and never stop a prescribed medicine without medical advice.

Palpitations and histamine questions answered

Can histamine intolerance cause heart palpitations?

A fast or irregular heartbeat is listed among the possible symptoms of histamine intolerance. Histamine widens blood vessels and acts on H2 receptors in the heart, which can raise heart rate. Other causes are more common, so palpitations should always be checked by a doctor first.

How soon after eating can histamine palpitations start?

People who notice a food link often describe symptoms within an hour or so of eating, usually alongside flushing, headache or digestive symptoms. Timing varies, and a diary over several weeks is more useful than a single episode.

Why does wine make my heart race?

Alcohol can raise heart rate and affect heart rhythm on its own. Wine, especially red wine, also contains histamine and other amines, and alcohol may interfere with histamine breakdown. Heavy drinking can trigger rhythm problems that need medical care.

Can antihistamines stop palpitations?

Antihistamines are not a treatment for palpitations in general. If your doctor thinks histamine is involved, they may suggest one as part of a wider plan. Some older antihistamines can themselves raise heart rate, so ask your doctor or pharmacist which is suitable.

What tests should I ask for?

Doctors usually start with an ECG, blood tests for anaemia and thyroid function, a blood pressure check and a review of medicines. If episodes come and go, a heart monitor worn for a day or longer may be arranged.

Should I stop my heart medicine if it is on a DAO inhibitor list?

No. Never stop or change a heart medicine without talking to your doctor. Stopping some heart medicines suddenly can be dangerous. Your doctor can review whether any change is appropriate.

Medical disclaimer: This content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting any supplement regimen.