Chronic obstructive pulmonary disease
The tissue of the lungs can be affected by a number of respiratory diseases, including pneumonia and lung cancer. Chronic obstructive pulmonary disease includes chronic bronchitis and emphysema, and can be related to smoking or exposure to harmful substances. A number of occupational lung diseases can be caused by substances such as coal dust, asbestos fibres, and crystalline silica dust. Diseases such as bronchitis can also affect the respiratory tract. Medical terms related to the lung often begin with "pulmo-", from the Latin "pulmonarius" (of the lungs) as in pulmonology, or with "pneumo-" (from Greek πνεύμων "lung") as in pneumonia.