Diffuse alveolar hemorrhage is a syndrome of recurrent or persistent bleeding into the lungs, caused most often by an autoimmune disorder.
Diffuse alveolar hemorrhage is a syndrome, not a particular disorder. It involves damage to the small blood vessels that supply the lungs, causing blood to accumulate in the tiny air sacs (alveoli) of the lungs. Such blood vessel damage can result from several disorders.
Among the disorders that can cause diffuse alveolar hemorrhage are the following:
Mild diffuse alveolar hemorrhage syndrome can cause cough, difficulty breathing, and fever. When the disorder is severe, people may have more difficulty breathing. They may gasp and have bluish discoloration of the skin (cyanosis). Some people die. At least two thirds of all people with diffuse alveolar hemorrhage cough up blood. People may also have other symptoms typical of the disorder that caused the diffuse alveolar hemorrhage. People who have repeated episodes of bleeding into the lungs can develop anemia (often causing fatigue) and lung scarring that causes chronic obstructive pulmonary disease (COPD—see Chronic Obstructive Pulmonary Disease (COPD)).
Doctors can often diagnose diffuse alveolar hemorrhage syndrome by a person's symptoms and chest x-ray findings. Chest x-rays typically show abnormal white patches in the lungs caused by lung bleeding. If the diagnosis is not clear based on symptoms and chest x-ray findings (for example, if the person has not coughed up blood), doctors may need to insert a flexible viewing tube into the lungs (bronchoscopy) and wash out the lungs with fluid (bronchoalveolar lavage) to check for small amounts of blood. The level of red cells in the blood is measured to test for anemia.
After diffuse alveolar hemorrhage has been diagnosed, the cause must be determined. A variety of tests may be done, depending on what disorders seem to be likely causes. Urinalysis is done to tell whether the person has kidney damage, characteristic of the pulmonary-renal syndrome (see Pulmonary-Renal Syndrome).
The disorder causing diffuse alveolar hemorrhage is treated. Autoimmune disorders are commonly treated with corticosteroids (such as prednisone) and sometimes cyclophosphamide (a chemotherapy drug) or other drugs that suppress the immune system. Problems that people with diffuse alveolar hemorrhage also have, such as difficulty breathing and clotting disorders, are also treated. For example, people may be given oxygen or may need to be on a ventilator for a period of time. Blood transfusions or other measures may also be needed.
Last full review/revision May 2013 by Marvin I. Schwarz, MD