Asthma

Several things happen to the airways when a person with asthma is exposed to certain triggers:
•    The lining of your airways becomes swollen and inflamed.
•    The muscles that surround your airways tighten.
•    The production of mucus is increased, leading to mucus plugs.

The basic cause of asthma is not yet known. Some scientists theorize that the decline in serious illness may be one factor in the increase of allergic asthma. They believe it is possible that an underused immune system may overreact to lesser irritants, inappropriately triggering the release of histamine and other inflammatory substances in the lungs. Other researchers believe the increased amount of time children are spending indoors is increasing their exposure to carpeting and other allergy triggers. Asthma is not caused by emotional factors, as commonly believed years ago. Emotional anxiety and nervous stress can, however, directly affect your immune and respiratory systems, and increase asthma symptoms or aggravate an attack. These reactions are considered to be more of an effect than a cause.

Although anyone can have asthma, it most commonly occurs in:
•    Children and adolescents ages 5-17
•    Females
•    People living in urban communities

Other factors include:
•    Family history of asthma
•    Personal medical history of allergies