Allergies

What is an allergy?

An allergy is when your body reacts to something that would usually be harmless.  It can be normal, everyday things like animals, dust or pollen.  Some people are allergic to certain foods.  Most allergies are mild and unthreatening but some can be very dangerous.

Causes

Some of the most common allergens are:

• Animals, especially pets
• House dust
• Flower, tree and grass pollen
• Insects and their stings
• Medicines
• Food and drinks

Signs of an allergic reaction

An allergic reaction can begin within minutes of contact with the allergen, or after a few hours.

Common symptoms are:

• Itchy or watery eyes
• Sneezing or a runny nose
• A rash or itchy skin
• Swollen eyes or lips
• Wheezing or difficulty breathing

The NHS recommends that you call 999 if:

• your lips, mouth, throat or tongue suddenly become swollen
• you’re breathing very fast or struggling to breathe (you may become very wheezy or feel like you’re choking or gasping for air)
• your throat feels tight or you’re struggling to swallow
• your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
• you suddenly become very confused, drowsy or dizzy
• someone faints and cannot be woken up
• a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)

These can be signs of anaphylaxis, which is a very serious allergic reaction that needs immediate treatment in hospital.

 

Treatments for allergies

There are many different ways to treat and manage allergies at home.

• Try to avoid the thing you’re allergic to whenever possible
• Consider medicines for allergic reactions, like antihistamines and steroid nasal sprays, tablets and creams – always read the label
• Speak to your GP or pharmacist for prescription medicine

Please note – The content on this website is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you are feeling unwell, make an appointment to see your GP or contact NHS 111. In an emergency, dial 999.

Last updated: July 22, 2026