Clubbing may result from chronic low blood-oxygen levels. This can be seen with cystic fibrosis, congenital cyanotic heart disease, and several other diseases. The tips of the fingers enlarge and the nails become extremely curved from front to back.

This chest x-ray shows stage II coal worker's pneumoconiosis (CWP). There are diffuse, small light areas on both sides of the lungs. Other diseases that may explain these x-ray findings include simple silicosis, disseminated tuberculosis, metastatic lung cancer, and other diffuse, infiltrative pulmonary diseases.

This chest X-ray shows coal workers pneumoconiosis - stage II. There are diffuse, small (2 to 4 mm each), light areas throughout both lungs. In the right upper lung (seen on the left side of the picture), there is a light area (measuring approximately 2 cm by 4 cm) with poorly defined borders, representing coalescence (merging together) of previously distinct light areas. Diseases which may explain these X-ray findings include simple coal workers pneumoconiosis (CWP) - stage II, silico-tuberculosis, disseminated tuberculosis, metastatic lung cancer, and other diffuse infiltrative pulmonary diseases.

This picture shows complicated coal workers pneumoconiosis. There are diffuse, small, light areas (3 to 5 mm) in all areas on both sides of the lungs. There are large light areas which run together with poorly defined borders in the upper areas on both sides of the lungs. Diseases which may explain these X-ray findings include complicated coal workers pneumoconiosis (CWP), silico-tuberculosis, disseminated tuberculosis, metastatic lung cancer, and other diffuse infiltrative pulmonary diseases.

Air is breathed in through the nasal passageways, travels through the trachea and bronchi to the lungs.