Up to 20% of people are affected by hay fever at some in their lives.
Hay fever occurs when affected people experience an allergic reaction to pollen.
Pollen is fine powdery grains released by plants as part of their reproductive system. When these tiny grains come into contact with your eyes, nose, mouth and throat, they can trigger an immune response causing the body to react with swelling, irritation and inflammation.
Common symptoms include sneezing, coughing, blocked or runny nose, itchy eyes, throat, mouth, nose and ears etc.
Hay fever is generally seasonal as many experience symptoms when the pollen count is high. This usually occurs between March and September.