Adenoids: Glands or lymphoid tissue in the upper part of the throat behind the nose.
Adenoidectomy: The surgical removal of adenoids which may help prevent blockage of the nasal passageways and Eustachian tubes. This may help to reduce recurrent sinus and ear infections, among other conditions. This is usually done as an outpatient procedure under general anesthesia.
Allergy: An exaggerated response to a substance or condition produced by the release of histamine or histamine-like substances in affected cells in the body.
Allergy index: Measure of allergy sufferers who are affected by pollen in your region. Since some types of pollen may be more likely to cause allergies than others, a high allergy index does not necessarily correspond to a high pollen count.
Angioedema: Swelling similar to urticaria (hives), but the swelling occurs beneath the skin instead of on the surface. Angioedema is characterized by deep swelling around the eyes and lips and sometimes of the hands and feet.
Antibodies: Specialized proteins produced by lymphoid cells (B cells) that circulate in the blood. Antibodies seek and attach to foreign proteins, microorganisms, or toxins in order to neutralize them. They are part of the immune system.
Antigen: A substance, usually a protein, which the body perceives as foreign.
Anti-inflammatory: Type of medication that reduces swelling and inflammation.
Asthma: A disease of the branches of the windpipe (bronchial tubes) that carry air in and out of the lungs. Asthma causes the airways to narrow, the lining of the airways to swell, and the cells that line the airways to produce more mucus. These changes make breathing difficult and cause a feeling of not getting enough air into the lungs.
Bronchodilators:Medications used to relax the muscle bands that tighten around the airways during an asthma episode. Bronchodilators also help clear mucus from the lungs.