The New Dictionary of Cultural Literacy, Third Edition. 2002.
asthma
(AZ-muh) A chronic disease of the respiratory system, characterized by sudden, recurring attacks of difficult breathing, wheezing, and coughing. During an attack, the bronchial tubes go into spasms, becoming narrower and less able to move air into the lungs. Various substances to which the sufferer has an allergy, such as animal hair, dust, pollen, or certain foods, can trigger an attack.