[Chronic obstructive pulmonary disease].

Conditions classified as chronic obstructive pulmonary disease are typically very slowly progressive in nature. They often begin early in life and may span a period of 15 to 35 years. Many individuals in the early stages will exhibit no symptoms of a clinical nature. Coughing and expectoration are the first manifestations of the disease process. The disease process is often associated with and exacerbated by cigarette smoking and exposure to air pollution. In the more severe stages of chronic obstructive pulmonary disease it is not uncommon to find patients being permanently and totally disabled. In fact this group represents one of the largest patient populations receiving permanent and total disability benefits under the Social Security Disability Insurance program.