Bronchoalveolar lavage
（重定向自Bronchoalveolar lavage fluid）
Bronchoalveolar lavage (BAL; informally, "bronchoalveolar washing") is a medical procedure in which a bronchoscope is passed through the mouth or nose into the lungs and fluid is squirted into a small part of the lung and then collected for examination. It is typically performed to diagnose lung disease.