Asthma is a chronic inflammatory condition characterized by reversible or at least partially reversible constrictions of the bronchi in the lungs. Bronchi are muscular tubes that carry air throughout the lungs, transporting it to and from smaller airway branches called bronchioles. With asthma, the walls of the bronchi are inflamed and swollen. This narrows the airway and makes it more difficult to breathe, resulting in wheezing, breathlessness, or coughing. Acute asthma attacks or episodes increase this effect by constricting bronchi muscles and producing excess amounts of mucus. The diameter of the bronchi may decrease to the point that very little air can travel in or out. This causes the person affected to cough and wheeze, feel tightness in their chest, and struggle to breathe. Although the cause is not clear, asthma attacks can occur at any time but are especially frequent at night and in the morning. Severe asthma attacks can be life threatening, often requiring immediate medical attention.

About 22 million people in the United States have asthma. An estimated 6 million of those affected are children, making asthma one of the most common chronic diseases in children. Before puberty, asthma affects more boys than girls. After puberty, it affects more girls. The condition is more prevalent in urban areas than rural and in those of African and Hispanic descent than in Caucasians. Asthma is not currently preventable or curable, but it is controllable and most people who have it can lead active, relatively normal lives.

Asthma is separated into four categories based on the severity and frequency of the patient’s symptoms. These categories include mild intermittent, mild persistent, moderate persistent, and severe persistent. Those with mild intermittent asthma may only have occasional episodes and no symptoms at other times. Those with severe persistent asthma may require multiple daily medications to control their condition.

The exact cause of asthma is unknown, but it is a complex interaction of different factors. The triggers for asthma attacks will be slightly different for each person. Many people with asthma, but not all, are allergic to specific substances. Asthma attacks can be triggered in these people by the allergens that they are sensitive to. The bronchi over-react to airborne allergens found in the home, work place, and environment such as pollen, pollution, mold, dust mites, animal dander, cockroaches, particles, and fumes. Asthma attacks may also be caused by stress, strong emotional response (laughing, crying, and anger), exercise, and exposure to cold air. Medicines such as some beta-blockers and aspirin, sulfites found in wine and dried fruit, and infections can cause episodes in some people.

Other lung diseases and conditions can have symptoms similar to asthma, co-exist with asthma, and/or can exacerbate asthma. Conditions such as GERD (gastroesophageal reflux disease, also called acid reflux) can trigger or worsen asthma attacks in some people.

Asthma Guidance
In August 2007, the National Heart, Lung, and Blood Institute (NHLBI) National Asthma Education and Prevention Program (NAEPP) released “Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma.” These updated guidelines are intended to help guide the diagnosis and monitoring of asthma patients. They focus on assessing and monitoring asthma, educating patients and encouraging them to participate in the management of their condition, controlling environmental factors that can trigger or exacerbate asthma attacks, and the use of medications. They recommend evaluating the impairment that a patient has and their risk of medication side effects, asthma exacerbations, and loss of lung function.