Allergies are your body’s immune system responding to foreign substances called allergens. Allergens themselves may not be harmful, but in some people they cause the immune system to over-react resulting in an allergic reaction. Allergic reactions vary and include many different symptoms. Some reactions such as anaphylaxis can be severe and threaten life, others can be a runny nose as with Hay Fever. Testing for allergies can be complicated, but is not always needed. Medication, including antihistamines, can work well for many types of allergy.

Read our overview of allergies now »


is an extreme and potentially life-threatening allergic reaction! It can cause swelling of the lips and tongue, breathing problems, collapse, leading to death, and is a medical emergency. If you suspect someone is suffering anaphylaxis:


Read more about anaphylaxis

Symptoms that may indicate an allergic reaction

Did you know?
If you have asthma you are also susceptible to hay fever

Find out more »
Dr Sarah Jarvis