After doctors complete the medical history and physical examination, they often take a chest x-ray. The results of the history, physical examination, and chest x-ray often suggest what additional testing may be needed to determine what is causing the person's symptoms.
Doctors may test for lung disorders by measuring the lungs' capacity to hold and move air and to absorb oxygen. These tests (called pulmonary function tests) are most helpful in determining the general type of lung disorder and determining the severity. Other tests, including additional chest imaging, bronchoscopy, and thoracoscopy, allow doctors to determine the specific cause of a lung disorder.
Because heart disorders may also cause shortness of breath and other symptoms that may suggest a lung disorder and because lung disorders can affect the heart, doctors often do electrocardiography (ECG, to measure the electrical impulses in the heart) and echocardiography (ultrasonography of the heart) in people with these symptoms.
Pulmonary artery catheterization is occasionally used to measure the effect of lung disease on heart function. This procedure is done by passing a long, thin plastic tube (catheter) through a vein, into the heart. and then into the pulmonary artery. Measurements can be taken through the catheter, or dye can be injected through it to look for clots or other abnormalities in the blood vessels of the lung (pulmonary angiography).