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Asthma

Glossary: Asthma

Friday, March 16, 2012 - 17:04

Contributing Author: Guy Slowik FRCS

Here are definitions of medical terms related to asthma in adults.

Allergen: A foreign substance that triggers an allergic response in a susceptible person. Allergens are usually common items encountered in everyday life such as substances from insects, animals or plants (such as pollen).

Allergy: An unusual response to a small amount of a foreign substance that normally does not cause a reaction in another person.

Asthma: A chronic, reversible obstruction of the airways. Allergic asthma is caused by an allergic stimulus; most common in children and adults; caused by exposure to substances such as dust mites, plants, pollens, and molds. Nonallergic asthma is caused by exposure to substances or conditions such as cold air, exercise, or respiratory infections, rather than exposure to allergens.

Asthma attack; asthma episode: The development of asthma symptoms, usually at rest, which are not immediately relieved by "rescue" or "reliever" medications; symptoms include coughing, wheezing, and shortness of breath caused by narrowing of the airways.

Chest tightness: A symptom of asthma caused by overinflation of the lungs due to the difficulty in pushing air out through obstructed air passages.

Dry powder inhaler (DPI): A portable device used to deliver dry powdered medication to the lungs; single and multi-dose models are available; no propellant is required; all models are breath-actuated and require no hand-lung coordination.

Inflammation: A tissue reaction in which increased numbers of cells invade the tissues. These cells release chemicals that cause changes such an increase in mucus production, swollen linings of airways, and constriction of the airways due to muscle spasm.

Metered-dose inhaler (MDI): A portable device used to deliver a fine aerosol mist of medication to the lungs; powered by propellant; use of the inhaler must be coordinated with the intake of breath.

Mucus: The secretion normally released into the airways to coat and protect them; mucus normally traps inhaled smoke and dust particles to prevent them from reaching deeper into the lungs.

Peak flow meter: A small, portable monitoring device that measures the amount of effort to force air out of the lungs; obstructive diseases such as asthma often cause an increase in the effort to breath out, which shows as a decreased value on the peak flow meter.

"Preventer" medication: A group of asthma drugs that prevent the symptoms of asthma by controlling the production, release, or activity of inflammatory chemicals, or by providing long-acting relaxation of airways (such as for 12 hours). Examples are inhaled corticosteroid, oral corticosteroid, leukotriene modifier, long-acting beta2-bronchodilator, nonsteroidal antiallergic, theophylline bronchodilator.

"Reliever" medication: A group of asthma drugs that counter, or relieve, the symptoms of asthma by causing the relaxation of airways. Examples are short-acting beta2-bronchodilator, anticholinergic bronchodilator.

Small-volume nebulizer (SVN): A device that uses a small compressor, nebulizer, and face mask to deliver a fine aerosol mist of drug to the lung; no hand-lung coordination required; units are bulky and not portable.

Spacer device: A small tube-like device, usually made out of plastic, to which a pressurized metered-dose inhaler (MDI) is attached; depression of the MDI canister delivers a dose to the spacer which holds it long enough for the medication mist to turn into a very fine cloud of vapor that is inhaled when a breath is taken.

Trigger: An irritating substance or condition to which a person reacts when they are exposed.

Wheeze: A symptom of asthma caused by the whistling sound made when air is pushed past an obstruction or narrowed area of an airway.

Asthma