Asthma is a condition in which your airways narrow and swell and may produce extra mucus. This can make breathing difficult and trigger coughing, a whistling sound (wheezing) when you breathe out and shortness of breath.

For some people, asthma is a minor nuisance. For others, it can be a major problem that interferes with daily activities and may lead to a life-threatening asthma attack.

Symptoms: 

Shortness of breath, Chest tightness or pain, Wheezing when exhaling, which is a common sign of asthma in children, Trouble sleeping caused by shortness of breath, coughing or wheezing attacks that are worsened by a respiratory virus, such as a cold or the flu.