Beginning 12 hours before bronchoscopy is carried out, you will not eat or drink. You will receive a mild pre-medication to help you relax. After a local anaesthetic, a flexible, optical tube will be inserted through the nose or mouth and into the lung for inspection. The doctor will check for any abnormalities and obtain a cell sample for analysis. The inner surface of the airways will be brushed in order to obtain bronchial cells and white cells will be washed out of the alveoli.