Allergic rhinitis, often called hay fever, occurs when your overreacts to particles in the air that you breathe-you are allergic to them. Your immune system attacks the particles in your body, causing symptoms such as sneezing and a runny nose. The particles are called , which simply means they can cause an .
An allergic reaction occurs only in people who have a condition called . It means that allergens are likely to cause an allergic reaction. An atopic person often develops more than one allergy. Experts don't know why people become atopic and have allergic reactions. Most people who have allergies have family members who also have some kind of allergy.
The first time you are exposed to an allergen in the air, your body's immune system may recognize the allergen as a foreign substance. Your body reacts by making against the allergen. The next time you are exposed to the allergen, the antibodies attack it, releasing histamine and other chemicals that cause the symptoms of your allergy. This is called sensitization. Sensitization may occur early in life. Children who develop allergic rhinitis may become allergic to many allergens, including , on cats and dogs, and tree and grass pollens.
See a picture of how an .
If you have a pollen allergy, your symptoms may vary according to the climate and the types of plants that grow in your area. If you have symptoms in:
- Winter and spring, you are probably allergic to tree pollens.
- Summer, you are probably allergic to grass and weed pollens.
- Late summer and fall, you probably are allergic to ragweed or other weed pollens, such as tumbleweed or sage.
Allergic rhinitis can affect your health if you do not treat it. If it lasts a long time, you may have complications such as , plugged ears and . Some people with allergic rhinitis have . Some have asthma, and researchers are looking at whether allergic rhinitis may lead to asthma.
Allergic rhinitis can also affect your quality of life. You may avoid seeing people, have problems sleeping, and feel tired or irritable. You may have trouble with school or work.