Hay fever is sometimes called seasonal allergic rhinitis because it only occurs during the pollen season. Perennial allergic rhinitis occurs all the year round. The conditions have the same type of symptoms and occur when an allergy causes inflammation and irritation of the delicate linings of the nose and eyes.
Hay fever is caused by breathing in pollen and by pollen getting in the eyes.
You can get hay fever at any time from early spring to late autumn, depending on what pollen or pollens you are allergic to. The pollens most likely to cause problems are those from grasses and trees - especially birch trees. Hay fever and perennial allergic rhinitis tend to run in families. You may need to try a number of different treatments and may find that a combination of treatments works best for you. The earlier you treat hay fever, the less you will suffer.