Asthma is a long-term (chronic) condition that causes repeated (recurrent) swelling and narrowing of the airways. The airways are the passages that lead from the nose and mouth down into the lungs. When asthma symptoms get worse, it is called an asthma flare, or asthma attack. When this happens, it can be difficult for your child to breathe. Asthma flares can range from minor to life-threatening.