Hay fever is an allergic reaction of the nasal passages to wind-borne pollens.
Most people with hay fever are allergic to ragweed pollen, but various grass and tree pollens are culprits as well. Generally if hay fever is worse in the spring it is due to tree pollens, if worse in the summer, grass and weed pollens are responsible. Conventional treatment is with a variety of antihistamines and sometimes cortisone drugs to relieve the symptoms. Helpful measures include avoiding the airborne pollens as much as possible. Indoors it can be helpful to utilize an air purifier.