Pulmonary” means “of the lungs.” This series of tests can give your doctor an idea of how well your lungs are working. These tests may be done if you’re having trouble breathing, if you feel a tightness in your chest, or if you get tired easily when walking or climbing stairs. If you have symptoms of a lung infection, like PCP, your doctor may order these tests, as well as blood tests and an X-ray of your lungs. The tests are simple: first, you will be asked to breathe out though a tube in your mouth, as hard and as fast as you can. The tube is connected to a machine which measures the flow of air, the rate of the flow, and the volume of air. Second, you will be asked to breathe in through the tube, as deeply as you can. The results of these tests can help your doctor figure out the cause of your shortness of breath.