Generally speaking, an asthma attack is usually caused by exposure to a trigger or allergen such as pet dander, pollen or dust. Symptoms of an asthma attack frequently include coughing, tightness in the chest, excess mucus production, shortness of breath, and/or wheezing. When an asthma attack occurs, it causes the body to produce increased amounts of naturally occurring substances found in the lungs called leukotrienes. Recent research has linked increased levels of leukotrienes to the inflammation associated with the symptoms of asthma.

Between three and six percent of the total population in developed countries have asthma. However, in Papua New Guinea, asthma used to be so rare that there was no native word for the disease.