Bronchoalveolar lavage is a medical procedure used to collect samples from the lungs. During this procedure, a thin tube called a bronchoscope is inserted into the airways. A sterile saline solution is then introduced into a specific area of the lung and subsequently suctioned back out, capturing cells, fluid, and other substances for analysis. This technique helps doctors diagnose various lung conditions, such as infections, inflammation, or cancer. By examining the collected samples, healthcare professionals can gain valuable insights into the patient's respiratory health and determine appropriate treatment options.