MODEL RELEASED. Asthma attack. 18-year-old male cyclist having an asthma attack. Asthma is a lung disorder in which attacks of breathlessness, wheezing and coughing are caused by the narrowing of airways in the lungs. An attack can be treated by the use of an inhaler (not seen), which dispenses a bronchodilator drug to widen the airways and aid breathing. An asthma attack may be triggered by exercise.