COPD is an acronym that stands for Chronic Obstructive Pulmonary Disease. It is used as a generic term to cover chiefly chronic bronchitis and emphysema, since these are the two major lung diseases which obstruct airways.
Official estimates of COPD victims range everywhere from 12 million to 32 million in the U.S. alone. According to the Merck Manual, it is the 4th leading cause of death in the country, killing more than 120,000 people each year.
In chronic bronchitis the lining of the bronchial tubes (branching off the trachea and leading to the alveoli) become swollen and fill with mucus. That blocks airflow and increases chest pressure. In emphysema, the alveoli (the tiny sacs that exchange oxygen and carbon dioxide into and out of the blood) themselves become irritated.
Ironically, the obstructive character of COPD doesn’t reduce air intake. It actually traps air inside the lungs, reducing the efficiency of exhalation. That makes it harder to breathe. Also, it lowers the number of capillaries in the alveolar walls, reducing the efficiency of oxygen-CO2 exchange that is central to respiration.
Subsidiary effects are then produced.
One, for example, is increased blood pressure in the arteries, as the body tries to compensate for lower oxygen levels. At the same time, the disease stimulates bone marrow (the source of new red blood cells) to increase production.
The exact causes of COPD are not known, but there are several risk factors strongly correlated with the disease.
Long-term cigarette smoking is known to irritate airways and injure the ability of alveoli to recover from its effects. Occupational exposure to certain chemicals and dust (such as one type of asbestos not commonly used in buildings) are another risk factor. Genetics plays a role, though how large and exactly how is still under investigation.
Symptoms of COPD include a newly developed chronic hacking cough, one that isn’t an effect of a cold and persists for more than a couple of months. The cough typically produces sputum, which can be examined as part of a diagnosis. Shortness of breath, called dyspnea, is an overwhelmingly common symptom among COPD sufferers, since both chronic bronchitis and emphysema reduce oxygen-absorption efficiency. Patients may also cough up blood, an event known as hemoptysis.
However, since all these symptoms can also accompany lung cancer and other diseases, only a professional diagnosis can determine the actual condition. Other symptoms will be taken into account during that procedure, including cyanosis, for example. Due to reduced oxygen absorption, the skin turns slightly bluish. Physicians can also gain clues from the shape of the chest, since COPD tends to produce a barrel shape from muscle realignment as the body compensates for the disease.
Tragically, many COPD cases are progressive. However, while there is no known cure for COPD in any of its forms, treatments can lessen the severity of symptoms and prolong survival. Changes of lifestyle are often imperative, such as cessation of smoking and reduced activity. But with accurate diagnosis and proper treatment, COPD need not be fatal.