Your mouth and lungs are connected through a pipe called trachea which is also called the windpipe. When there is a blockage in your trachea or windpipe due to smoke, sputum is formed. Also known as phlegm. When you cough, sputum comes out of your mouth.
Test Method: In this test, your doctor will insert a tube through your mouth. The tube has a camera attached to it. The tube will try to pull sputum from inside the windpipe and a sample will be collected.
Test Report: The usual turn around time is 24 to 48 hours.