Glossary: Asthma

Content provided by the Faculty of the Harvard Medical School

Glossary

allergen: A substance that stimulates the immune system to produce an allergic reaction. In asthma, this substance is almost always inhaled.

beta-agonists: Members of one family of bronchodilator medicines. They are all related to adrenaline (epinephrine) and cause bronchial muscles to relax by stimulating receptor molecules on smooth muscle, called beta receptors. Beta-2 agonist drugs are designed to minimize heart stimulation.

beta blockers: Medications used to treat a variety of illnesses, including heart disease, high blood pressure, and migraine headaches. They function in exactly the opposite way from beta-agonists. They can worsen asthma control and cause asthma flare-ups.

bronchial tubes: The system of branching tubes that carries air from the windpipe to the tiny air sacs of the lungs.

bronchodilator: A type of medication that acts to open the breathing passages primarily by relaxing the muscles surrounding the bronchial tubes.

controllers: Asthma medications taken on a daily basis to prevent or control asthma symptoms.

corticosteroids: A family of medications designed to reduce inflammation. These anti-inflammatory drugs are often referred to as "steroids," but are different from the muscle-building steroids used illegally by some competitive athletes.

dry-powder inhaler: A device for delivering inhaled medication that works differently from a metered-dose inhaler. With a dry-powder inhaler, an aerosol of medicine is created by the force of inhalation rather than by a chemical propellant.

immunoglobulin E (IgE): Antibodies the body makes as part of the immune response to parasites and allergens.

inflammation: Inflammation in asthma refers to swelling of the bronchial tubes and infiltration of their walls by immune cells. This kind of inflammation renders the bronchial tubes more sensitive, or "twitchy," in response to a variety of stimuli, and it can cause swelling sufficient to narrow the air passageways.

leukotriene modifiers: Asthma medications that work by blocking the production or action of leukotrienes, chemicals made in the body as part of an allergic reaction.

metered-dose inhaler: A device for delivering inhaled asthma medications. Multiple doses of medication are held within a pressurized canister. With each use, the exact "metered" dose is released in the form of a spray.

nebulizer: A device that takes a liquid form of medicine and converts it into a mist to be inhaled.

NSAIDs: Nonsteroidal anti-inflammatory drugs, used to treat inflammation, fever, and pain. NSAIDs do not treat the inflammation of asthmatic airways. People with aspirin-sensitive asthma suffer flare-ups of symptoms after taking NSAIDs.

peak flow: A measure of how fast you can blow air out of your lungs. In asthma, your peak flow reflects the extent to which your bronchial tubes are normally open or abnormally narrowed.

peak flow meter: A simple hand-held device used to measure peak flow.

quick relievers: Medications that quickly open the bronchial tubes by relaxing the muscles surrounding these airways. Quick relievers can be used as needed for relief of asthmatic symptoms rather than on a regular schedule.

spacer: A hollow chamber into which inhaled medicines can be squirted before inhalation. They are used with metered-dose inhalers to help deliver medicine effectively to the bronchial tubes and to reduce the amount of medicine left behind on the tongue and throat.

spirometry: A simple, painless breathing test performed in a physician's office or pulmonary function laboratory that measures how fast you can force air from your lungs and the total amount of air you can empty from your lungs.

steroids: Another term for corticosteroids.

trigger: Anything that can set off asthma symptoms.

Last updated:	September 27, 2007