Cough

A cough is a sudden, often repetitive, spasmodic contraction of the thoracic cavity, resulting in violent release of air from the lungs, and usually accompanied by a distinctive sound. Coughing is an action the body takes to get rid of substances that are irritating the air passages. A cough is usually initiated to clear a buildup of phlegm in the trachea; air may move through this passage at up to 480 km/h (300 mph) during a contraction. Coughing can also be triggered by a bolus of food go ...