Your doctor will probably do a chest X-ray if he or she suspects you have chronic obstructive pulmonary disease (COPD).

A chest X-ray provides a picture of the heart and lungs. Although COPD cannot be diagnosed with a chest X-ray alone, it can help your doctor evaluate shortness of breath, help support a diagnosis of COPD, and detect advanced emphysema.

A chest X-ray is done at the time of initial diagnosis of COPD. Although routine follow-up chest X-rays are not usually done, many doctors advise smokers and recent ex-smokers to have this test every 1 to 2 years.

Abnormal chest X-ray findings are usually not seen until COPD is severe. In this case, the X-ray may show:

• Flattening of the diaphragm, the large muscle that separates the lungs and heart from the abdominal cavity.
• Increased size of the chest, as measured from front to back.
• A long narrow heart.
• Abnormal air collections within the lung (focal bullae).

A normal chest X-ray does not mean you do not have COPD. It may be most useful for ruling out other conditions that might be causing your breathing problems, such as lung cancer, heart failure, pneumonia, or tuberculosis.