A procedure for collecting respiratory specimens from the airway, typically during bronchoscopy. Sterile saline is flushed through an airway, and the resultant mixture of cells, secretions, and saline is aspirated for studies (e.g., microscopy and culture).

This test uses an instrument called a bronchoscope--a long, narrow tube with a light at the end--to wash out, or lavage, cells and other materials from inside the lungs. This wash fluid is then examined for the amount of various cells and other substances that reflect inflammation and immune activity in the lungs. A high number of white blood cells in this fluid usually indicates an inflammation in the lungs.

Fluid obtained from the lung by bronchoscopy.

washing out of the lungs with saline or mucolytic agents for diagnosis or therapeutic purposes

Bronchoalveolar lavage (BAL) 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 recollected for examination. BAL is typically performed to diagnose lung disease. In particular, BAL is commonly used to diagnose infections in people with immune system problems, pneumonia in people on ventilators, some types of lung cancer, and scarring of the lung (interstitial lung disease).