Hay fever is also called allergic rhinitis. Although the cause of allergy in hay fever usually comes from a plant pollen, allergic rhinitis can have other causes. These can be things like feathers, dust, or animal dander. Sometimes it is hard to know whether a stuffy nose or itchy eyes is due to pollen or another cause. People with hay fever have developed antibodies against pollens that circulate in the blood stream and stay in the tissues of the nose and in the skin.
Antibodies react with pollen, causing histamine to be released in the blood.
This causes the lining of the nose, sinuses, eyelids, and eyes to swell. These allergic attacks may last 15 to 20 minutes, or for several days. People with hay fever usually have symptoms at the same time every year, when certain plants bloom. For many, hay fever is only a minor problem, but for others it interferes with daily activities. The best way to control the symptoms of hay fever is to avoid the pollens and dusts.