Adenoids
Glands or lymphoid tissue in the upper part of throat below the nose, also known as the pharyngeal tonsil.
Adenoidectomy
The surgical removal of enlarged adenoids to help prevent blockage of the pharynx (back of throat) or eustachian tubes. It may help prevent ear infections. This is usually done as an outpatient procedure under general anesthesia.
Allergen
A substance that your body perceives as foreign and harmful; initiates the allergic reaction.
Allergic rhinitis
See hay fever
Allergy
An exaggerated response to a substance or condition produced by the release of histamine or histamine-like substances in affected cells.
Allergy index
Measure (from 1-10) 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.
Allergy shots
See immunotherapy
Anaphylaxis
Severe, life-threatening allergic response that may be characterized by symptoms such as lowered blood pressure, wheezing, vomiting or diarrhea, and swelling and hives.
Angioedema
Swelling similar to urticaria (hives), but the swelling occurs beneath the skin instead of on the surface. Angioedema is characterized by deep swelling that commonly occurs around the eyes and lips and sometimes of the hands and feet.
Antibodies
Specialized proteins produced by white blood 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, that the body perceives as foreign.
Antihistamine
Medication that prevents symptoms of sneezing, itching, runny nose and possibly congestion by blocking histamine receptors.
Anti-inflammatory
Type of medication that reduce swelling and mucus production, particularly for asthma and rhinitis.
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 can cause a feeling of not getting enough air into the lungs or shortness of breath.
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.
Conjunctivitis
Conjunctivitis is an inflammation of the conjunctiva, the tissue that lines the inside of the eyelid. If the cause is bacterial infection, it is called “pink eye” or bacterial conjunctivitis. If the cause is allergic it is called allergic conjunctivitis.