How is the condition diagnosed?
The first step in figuring out the cause is a history and physical exam. This may be all that is needed to make the diagnosis. In other cases, further tests may be needed.
Different tests may be ordered, depending on the suspected cause. For instance, a type of breathing test called pulmonary function testing can help diagnose asthma and COPD. Chest x-rays are commonly used, and can help detect pneumonia, sarcoidosis, and other conditions. Special x-ray tests, such as a chest CT scan, may be needed in certain cases. For instance, a CT scan can help detect lung cancer.