ETYM Greek, short-drawn breath: cf. Skr. vâ, Goth. waian, to blow, Eng. wind.
Respiratory disorder characterized by wheezing; often of allergic origin; SYN. asthma attack, bronchial asthma.
Chronic condition characterized by difficulty in breathing due to spasm of the bronchi (air passages) in the lungs. Attacks may be provoked by allergy, infection, and stress. The incidence of asthma may be increasing as a result of air pollution and occupational hazard. Treatment is with bronchodilators to relax the bronchial muscles and thereby ease the breathing, and in severe cases by inhaled steroids that reduce inflammation of the bronchi.
Extrinsic asthma, which is triggered by exposure to irritants, such as pollen and dust, is more common in children and young adults. Less common, intrinsic asthma tends to start in the middle years. Approximately 5–10% of children suffer from asthma, but about a third of these will show no symptoms after adolescence, while another 5–10% of people develop the condition as adults. Growing evidence that the immune system is involved in both forms of asthma has raised the possibility of a new approach to treatment.
Although the symptoms are similar to those of bronchial asthma, cardiac asthma is an unrelated condition and is a symptom of heart deterioration.