Bronchoscopy is an endoscopic procedure of envisioning the inside of the air passages for diagnostic and therapeutic purposes. An instrument (bronchoscope) is inserted into the airways, consistently through the nose or mouth, or seldom through a tracheostomy. This allows the specialist to examine the patient's airways for abnormalities such as foreign bodies, bleeding, tumors, or inflammation. Specimens may be taken from inside the lungs. The construction of bronchoscopes ranges from rigid metal tubes with attached lighting devices to flexible optical fiber instruments with Real time video equipment.