Histamine: What It Is and What It Does
Histamine is a substance that your cells produce to help your immune system respond to allergy triggers1. It’s mostly recognised for its role in causing allergy symptoms2. For example, histamine can cause you to sneeze, feel itchy, or make your eyes tear up3. But it also plays a key role in additional tasks, such as regulating your sleeping and waking cycle and cognitive function2.
Read on to learn more about histamine, what it does, and how to deal with it in our dedicated guide. In this guide:
Histamine is an amine that is involved in immune responses throughout your body1. Amines are made of nitrogen atoms bound with other atoms. These can bond to other cells throughout your body to respond to injury or allergy triggers1.
What does histamine do?
Histamines play an important role in how your body responds to allergies1. Essentially, their job is to help rid your body of something that’s bothering you, such as an allergy trigger, or ‘allergen’3.
Most allergy triggers, such as pollen and pet dander, can often seem harmless, but your immune system can see them as a threat3. As a result, it can overreact and release histamine to help keep your body safe3. This can result in those familiar allergy symptoms, such as itching and sneezing3. That’s why people often use antihistamines to treat their symptoms3.
Sometimes people can have high levels of histamine in their body, which can result in histamine intolerance2. This can happen if your body can’t break down histamine like it’s supposed to2. This excess build-up of histamine can result in a range of symptoms such as2, 1:
Headaches
Migraines
Fatigue
Nasal congestion
Digestive problems
Irregular periods
Skin symptoms, such as hives or itchy skin
Dizziness
Anxiety
Abdominal pain, bloating and diarrhoea
High blood pressure
Changes to heart rate
Histamines can be triggered by allergens1. Common allergens include4:
Pollen (hay fever)
Certain types of foods, such as peanuts, milk and eggs
Other common histamine triggers include1:
Dust
Air pollution
Airborne chemicals, such as artificial fragrances
Eating large meals
Dehydration
What conditions involve histamine?*
Histamine plays a central role in several allergic conditions, including2:
Atopic dermatitis – also known as eczema
Contact dermatitis – can occur when your body encounters fragrances, metals, and preservatives
Allergic rhinitis – also known as hay fever, this can happen because of pollen, dust, mould etc.
Allergic asthma – can be triggered by all of the above.
Allergic conjunctivitis – can occur when the conjunctiva of your eyes gets swollen or inflamed because of allergens
There are various ways you can help keep your histamine levels in check2:
Antihistamines
Antihistamines, such as BENADRYL® Allergy Relief, can help treat allergy symptoms caused by triggers such as pollen and pet dander2. BENADRYL® Allergy Relief can be taken as required up to three times per day.
Corticosteroids
Corticosteroids can help with inflammatory allergy and histamine effects2. For example, topical corticosteroids can be used to reduce inflammation and irritation caused by conditions such as contact dermatitis and eczema5.
Histamine FAQs
Certain types of medications for blood pressure and depression can affect how diamine oxidase (the enzyme that breaks down histamine) is produced1. When your body doesn’t break down histamine as it should, this can lead to histamine intolerance, which can cause high levels of histamine to build up in your body1.
Histamines are chemicals produced by your immune system to protect your body from something that is bothering it, such as allergens3. They can cause allergy symptoms2, such as sneezing and itching3. Antihistamines, on the other hand, are medicines that help to manage allergy symptoms3.
Certain types of food are naturally high in histamines, such as cured meat, cheese, and canned fish6. Other types of food don’t contain much histamine but can trigger your white blood cells to make it6. These can include bananas, pineapples, and citrus fruits6.