Allergen: A substance that can trigger an allergic reaction. Asthma can be triggered by dust mites, animal dander, mold, and cockroaches.
Alveoli: The small units of lungs, these are tiny air sacs where oxygen is transferred into lungs and carbon dioxide waste enters the airways in order to be exhaled out.
Bronchodilators: Drugs that relax the muscles around the airways and help in opening up the airways.
Metered Dose Inhaler: The most common device people use to take asthma medication. An MDI allows you to inhale a specific amount of medicine (a "metered dose"). It consists of a metal canister, which keeps the medication under pressure, and a plastic sleeve, which helps to release the medication. When you press the canister, medicine particles are propelled toward your throat where you can inhale them.
Peak flow: A simple measurement of how well you can blow air out of your lungs. Peak flow meter is a small and inexpensive home device used to measure the peak flow.