Bronchoscopy with Bronchoalveolar Lavage (BAL) and biopsy is a procedure used to diagnose lung diseases by directly visualizing the airways and obtaining tissue samples. Dr. Mayank performs this procedure when there is suspicion of infections, tumors, or inflammatory diseases. The procedure helps in the diagnosis of conditions such as pneumonia, TB, and lung cancer. BAL involves washing the lungs with saline to collect cells, while biopsy provides a more definitive diagnosis of abnormalities.