One in five people will be affected by hay fever at some point in their lifetime.
Symptoms include sneezing, a runny nose and itchy eyes.
Allergies typically occur when the body reacts to substances it can’t tolerate. These substances, like pollen or dust mites, are called environmental allergens and are normally harmless - but the immune system of a person with allergies views them as harmful.
Allergic rhinitis, commonly known as hay fever, is an inflammation or irritation of the mucus membranes that line the nose, according to Health Feed.
Hay fever occurs when an allergen, such as pollen, causes your body to defend itself by producing antibodies. These antibodies then bind to mast cells, a process which releases a chemical called histamine.
The chemical causes dilation of nasal blood vessels and inflammation of the mucus membranes - which is why you sneeze a lot and get stuffy sinuses.
The best treatment for this is to avoid the allergen responsible, however when this is not possible there is medication available to help alleviate symptoms.
Antihistamine medication, for example, binds to receptors and works by blocking the binding of the cells which produce histamine.
Corticosteroids and decongestants may also help.
NHS Choices have issued four top tips for avoiding an allergic reaction to pollen:
:: Wear sunglasses to stop pollen getting in your eyes when you’re outdoors.
:: Take a shower and change your clothes after being outside.
:: If the pollen count is high, try and stay indoors.
:: Apply a small amount of Vaseline to your nasal openings (nostrils) to trap pollen.