Chest X-ray: An X-ray is the most common first test for lung problems. It can identify air or fluid in the chest, fluid in the lung, pneumonia, masses, foreign bodies, and other problems.
Computed tomography (CT scan): A CT scan uses X-rays and a computer to make detailed pictures of the lungs and nearby structures.
Pulmonary function tests (PFTs): A series of tests to evaluate how well the lungs work. Lung capacity, the ability to exhale forcefully, and the ability to transfer air between the lungs and blood are usually tested.
Spirometry: Part of PFTs measures how fast and how much air you can breathe out.
Sputum culture: Culturing mucus coughed up from the lungs can sometimes identify the organism responsible for a pneumonia or bronchitis.
Lung biopsy: A small piece of tissue is taken from the lungs, either through bronchoscopy or surgery. Examining the biopsied tissue under a microscope can help diagnose lung conditions.
Flexible bronchoscopy: An endoscope (flexible tube with a lighted camera on its end) is passed through the nose or mouth into the airways (bronchi). A doctor can take biopsies or samples for culture during bronchoscopy.
Rigid bronchoscopy: A rigid metal tube is introduced through the mouth into the lungs' airways. Rigid bronchoscopy is often more effective than flexible bronchoscopy, but it requires general (total) anesthesia.