Hay fever also known as allergic rhinitis is a form of allergy due to pollen of grasses, trees and other plants. Allergy is basically a disorder in which the body becomes hypersensitive to particular allergens (antigens), which provoke characteristic symptoms whenever they come in contact or are inhaled, ingested or injected. In allergic rhinitis the membrane lining the nose and sometimes the conjunctiva becomes inflamed. The symptoms of hay fever are sneezing, running nose/blocked nose and watering eyes.