Determine the Relationship Between Circadian Rhythms and Nocturnal Asthma

Asthma is a disease that affects the lungs. Symptoms include repeated episodes of wheezing, breathlessness, chest tightness, and nighttime or early morning coughing. Some people with asthma experience worse symptoms at night, which is known as nocturnal asthma (NA). The reason for the decline in lung function at night in some asthmatics is not well understood, but it may be linked to the human biological clock, which controls daily activity and sleep rhythms. To determine whether differences in biological clocks relate to worsening nocturnal lung function, this study will evaluate the circadian rhythms of people with NA, people with non-nocturnal asthma, and healthy people.