During this test a thin fibreoptic tube is inserted into your breathing tubes, through the mouth or nose, to view the tubes. Usually salty water is flushed down the scope and suctioned away and a biopsy may be taken. These tests are then sent to the laboratory for examination under a microscope. It is undertaken with use of sprays of local anesthetic to the back of the throat and breathing tubes. You will be given medicine into a needle inserted into your vein to make you sleepy and relaxed.  A specialist doctor does this procedure in an operating theatre environment.