Asthma Overview

Asthma is a chronic (long-term) respiratory disease that causes a person's bronchial tubes (the main airways in the lungs) to become inflamed. The inflammation causes the airways to become very sensitive to allergens (foreign substances that cause an allergic reaction) and other respiratory irritants. When exposed to an asthma "trigger," the airways become narrow and fill with mucus. People have difficulty breathing due to the reduced air flow.

An asthma attack is a sudden worsening of symptoms. During an asthma attack, people wheeze (husky or whistling breathing), cough, and experience shortness of breath. Although there is no cure for asthma, preventative measures and medications help people live active lives.

According to the American Lung Association, in 2004 approximately:

• 20.5 million Americans had asthma.
• 11.7 million of them had an asthma attack (including 4 million children under 18).
• 14.5 million lost work days were due to asthma.
• 25% of all emergency room visits were due to asthma.
• 44% of all asthma hospitalizations were children.
• 5,000 deaths were due to asthma.

Moreover, asthma cases occur more often in certain populations:

• 40% of children who have asthmatic parents will develop asthma.
• 35% more adult females have asthma than adult males.
• 39% more African Americans have asthma than Caucasians.