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. Pulse oximetry or arterial blood gas analysis helps determine the person's oxygen level and determine whether a breathing disorder is present. 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, exercise testing, bronchoscopy, and thoracoscopy, or lung biopsies, 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 (ultrasound of the heart) in people with these symptoms.
In addition to tests, procedures may be necessary to treat lung disease. These include suctioning, the use of a flexible tube to remove fluid from the airways; bronchoscopy, the use of a flexible scope to treat airway disease or take tissue samples; thoracentesis and chest tube insertion, to sample and drain fluid, air, or blood from the space around the lungs; and mediastinoscopy, mediastinotomy, thoracoscopy, and thoracotomy, to view and perform surgery inside of the chest. Note that many procedures can be used both to diagnose and treat lung disease.
