what causes hay fever

Hay fever is a common allergic condition caused by an allergic reaction to pollen, which is a fine powder released by plants as part of their reproductive cycle. The pollen contains proteins that can cause the nose, eyes, throat, and sinuses to become swollen, irritated, and inflamed. Other common allergens that can trigger hay fever symptoms include dust mites, pet dander, and mold. When you have hay fever, your immune system identifies a harmless airborne substance as being harmful and produces immunoglobulin E (IgE) antibodies to protect against this allergen. The next time you come in contact with the allergen, these antibodies signal your immune system to release chemicals such as histamine into your body, causing a reaction that leads to the symptoms of hay fever. You’re more likely to develop hay fever if you have a family history of allergies, particularly asthma or eczema, or if you have other allergies or asthma. Hay fever can often be controlled using over-the-counter medication from your pharmacist. For severe and persistent hay fever, there’s also a type of treatment called immunotherapy, which involves being exposed to small amounts of pollen over time to build resistance to pollen’s allergic effects.