American Medical Association Family Medical Guide - American Medical Association [387]
The bronchial tree
The lower end of the trachea (windpipe) divides into the two main airways to the lungs—the right and left main bronchi. The bronchi branch into many tiny airways called bronchioles.
Other Lung Problems
Some of the following terms are specific lung diseases or disorders; others are terms doctors use to describe symptoms of (or symptoms that result from) lung disorders:
• Adult respiratory distress syndrome Adult respiratory distress syndrome is a form of pulmonary edema (see right) that results from injury, infection, or, in rare cases, allergies.
• Alveolitis Alveolitis is inflammation of the alveoli (the tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place). It is a symptom of some allergies (see page 912) or of autoimmune disorders such as rheumatoid arthritis (see page 918).
• Chronic obstructive pulmonary disease Chronic obstructive pulmonary disease (also called chronic obstructive lung disease) is the general term for any progressive disease such as chronic bronchitis (see page 655) or emphysema (see page 656) that is characterized by a persistent obstruction of air flow into or out of the lungs.
• Interstitial fibrosis Interstitial fibrosis is thickening and scarring of fibrous tissue caused by an autoimmune disease, idiopathic pulmonary fibrosis (see page 645), occupational lung diseases (see page 645), tuberculosis, or fungal diseases (see page 662).
• Lung abscess A lung abscess is a contained infectious area in a lung.
• Pleural effusion Pleural effusion is an accumulation of fluid in the space between the pleura (the two membranes that surround the lungs) caused by infection, an autoimmune disease, injury to the chest wall, congestive heart failure, or a tumor (usually one that has spread to the pleura from another site).
• Pleurisy Pleurisy (also called pleuritis) is inflammation of the pleura (the two membranes that surround the lungs) usually caused by infection, congestive heart failure, injury to the chest wall, an autoimmune disease, or fluid in the abdomen.
• Pulmonary edema Pulmonary edema is a buildup of fluid in the lung tissue.
• Pulmonary empyema Pulmonary empyema is the presence of pus (which indicates inflammation and infection) in pleural effusion.
Asthma
Asthma is a chronic disease of the air passages (bronchi and bronchioles) of the lungs, characterized by inflammation and constriction of the smooth muscle of the airways and excess mucus production. The resulting swelling (of the airway wall and lining) and spasm (of the muscles in the bronchial walls) obstruct the airways, increase the effort it takes to breathe, and reduce the amount of oxygen the body can take in, causing asthma attacks.
Asthma attacks are usually triggered by viral infections (especially of the respiratory tract), medications, inhaled irritants (such as tobacco smoke, fumes, or pollutants), vigorous exercise, or stress. Allergies (such as to pets, pollen, mold, or some foods) can cause asthma attacks in some people. Other people may have symptoms only when they are exposed to cats or when they exercise in the cold (and breathe in cold air). The cause of asthma is often unknown.
Approximately 17 million Americans have asthma, including increasing numbers of children. Five to 10 percent of children have some form of asthma, compared with about 5 percent of adults. The disease has a genetic component; children who have a parent with asthma are more likely to develop asthma than children whose parents don’t have asthma. Most children eventually outgrow their asthma; however, it may recur after adolescence.
In the United States, about 5,000 deaths a year result from