The medical term for hayfever is seasonal allergic rhinitis. In other words, it’s an allergic condition that varies in prevalence, depending on the time of year.

Hayfever develops when the body’s immune system reacts to pollen as if it were something harmful, like an infection. Produced by plants, including grass, trees and weeds, pollen is harmless to most people, but for those with hayfever, contact with pollen triggers the body to release a type of antibody to attack the allergen (pollen). The immune system then releases chemicals, including histamine, to prevent the spread of what it thinks is an infection.

The symptoms and the severity of hayfever can vary widely from person to person and also depend on the type of pollen a person is allergic to. Common symptoms include:

• Sneezing
• Runny nose
• Nasal congestion
• Coughing
• Itchy eyes, ears, nose or mouth.

Less common symptoms include loss of smell, facial pain, headaches, earache, tiredness and fatigue. Many sufferers are often confused about whether they have a cold or hayfever. One of the key differences to look out for is how long the symptoms last for. A cold will usually clear up within two weeks, but hayfever symptoms will persist for longer.