[The lung as a reflection of internal medicine diseases]

The lungs are called "mirror of internal medicine" because they are often involved in multisystem diseases. The morphologic changes of the lungs are uncharacteristic and the classification is only possible in relation to other manifestations of multisystem diseases. In this article clinical syndromes with pulmonary manifestations will be reviewed. Congestive heart failure and congenital diseases may lead to pulmonary features. Most cardial pleural effusions are transudates except postcardiac injury syndrome causes pleural exsudates. Almost all connective tissue diseases may affect the lungs and the pleura. Scleroderma, systemic lupus erythematodes, vasculitis, polymyositis, Sharp's syndrome, Wegener's granulomatosis, Goodpasture and Sjögren's syndrome, rheumatoid arthritis, ankylosing spondylitis and sarcoidosis are discussed. There is an association of gastroesophageal reflux and asthma. Acute pancreatitis may cause an adult respiratory distress syndrome. Endocrine and hematologic diseases seldom cause pulmonary changes. Many malignant tumors are going along with metastasis in the lungs. Renal insufficiency causes "fluid lung", nephrotic syndrome pleural effusions. Finally different drugs induce pulmonary diseases.