Your doctor will usually use very simple tests to determine if you have a lung disease. He or she will take a medical history and give you a complete physical examination. Your examination may include some simple laboratory tests like a chest x-ray, blood tests, a phlegm (sputum) examination, and a pulmonary function test, which is a painless procedure that shows the doctor how well your lungs work when you breathe. Exercise testing may also be done to examine the body's response to exertion or physical activity.

Health authorities advise a tuberculosis (TB) skin test for various groups of people, including all persons who are HIV-positive, meaning that they have tested positive for the human immunodeficiency virus that causes AIDS. Since the TB test reaction may be misleading in AIDS, a chest x-ray and complete physical exam may be recommended even if the tuberculin test is negative.

Based on information gathered through these quick and basic tests, your doctor will decide which lung disease, if any, exists. Then, appropriate treatment can be started.