Asthma is a chronic (long-term) condition that affects the airways in the lungs. The airways are tubes that carry air in and out of your lungs. If you have asthma, the airways can become inflamed and narrowed at times. This makes it harder for air to flow out of your airways when you breathe out. According to the Centers for Disease Control and Prevention, 1 in 13 people in the United States has asthma. It affects people of all ages and often starts during childhood.

Source: NHI