If you frequently experience shortness of breath, coughing, or you hear a whistling or wheezy sound in your chest when you breathe, you may have asthma — a chronic condition that causes inflammation and narrowing of the bronchial tubes, the passageways that allow air to enter and leave the lungs. If people with asthma are exposed to a substance to which they are sensitive or a situation that changes their regular breathing patterns, the symptoms can become more severe.

Asthma symptoms affect an estimated 26 million Americans — 19 million adults and 7 million children — and are among the leading causes of absences from work and school. According to the World Health Organization, asthma often runs in families; about half the cases are due to genetic susceptibility, and half result from environmental factors. Although there is no cure for asthma, effective treatments are available. Asthma can be best managed by seeing an allergist.

There are two types of asthma: allergic (caused by exposure to an allergen) and non-allergic (caused by stress, exercise, illnesses like a cold or the flu, exposure to extreme weather, irritants in the air, or some medications). Many patients have both allergic and non-allergic asthma.