Nonspecific Chronic Lung Diseases

a group of chronic diseases of the bronchopulmonary system. Their causes and developmental mechanisms differ but they have certain clinical, functional, and morphological manifestations in common. These include cough, dyspnea, bronchial obstruction, and fibrosis, combined with degenerative and inflammatory changes in the bronchi, blood vessels, and parenchyma of the lungs. The term “nonspecific chronic lung diseases” was adopted for diffuse chronic bronchitis, bronchial asthma, and emphysema at a symposium held in London in 1959. At an international symposium held in Moscow in 1962, the term was extended to include chronic pneumonia, diffuse interstitial pulmonary fibrosis, and bronchiectasis. Pneumoconioses, tumors, and generalized lesions of the lungs caused by such specific infections as tuberculosis were excluded from the group.

Nonspecific chronic lung diseases constitute an increasingly important factor in the morbidity and mortality rates of many countries. The high incidence of these diseases results from air pollution, from the prevalence of smoking and of acute bronchitis and pneumonia caused by influenza and other infections, and from changes in the body’s susceptibility to infection.

The classification of nonspecific chronic lung diseases as a specific group is to some extent arbitrary. The main diseases in the group—chronic bronchitis, chronic pneumonia, and bronchial asthma—constitute an independent nosologic entity, require a different type of treatment, and are studied separately. Other diseases in the group—diffuse interstitial pulmonary fibrosis, acquired bronchiectasis, and emphysema—are classified as syndromes and are primarily complications of the nonspecific chronic lung diseases.

Some aspects of the terminology and classification of nonspecific chronic lung diseases remain in dispute. For example, the International Statistical Classification of Diseases, Injuries, and Causes of Death (1965) does not include chronic pneumonia, one of the common diseases in the group. Moreover, there are no universally accepted methods of classifying nonspecific chronic lung diseases. It is therefore difficult to correlate and evaluate the morbidity and mortality rates of these diseases in different countries and in studies by medical researchers.

Nonspecific chronic lung diseases may be prevented by observing methods of environmental conservation, educating the public on the dangers of smoking, developing systems of physical culture, and achieving early and complete cures in cases of acute pneumonia and bronchitis. Regular medical examinations serve to detect early forms of the diseases.