Chronic Obstructive Pulmonary Disease

Diagnostic Evaluation of COPD

Lung (pulmonary) function tests: Pulmonary function tests measure the amount of air inhaled and exhaled, and if your lungs are delivering enough oxygen to your blood.

Spirometry is the most common lung function test. Spirometer measures how much air lungs can hold and how fast air is blown out of your lungs. Spirometry can detect COPD even before symptoms of the disease arise. It can also be used to track the progression of disease and to monitor how well treatment is working. Spirometry often includes measurement of the effect of bronchodilator administration. Other lung function tests include measurement of lung volumes, diffusing capacity and pulse oximetry.

Chest X-ray: A chest X-ray can show emphysema, one of the main causes of COPD. An X-ray can also rule out other lung problems or heart failure.

CT scan: A CT scan of lungs can help detect emphysema and help determine the need for  surgery for COPD. CT scans can also be used to screen for lung cancer.

Arterial blood gas analysis: This blood test measures how well lungs are bringing oxygen into blood and removing carbon dioxide.

Laboratory tests: Laboratory tests aren't used to diagnose COPD, but they may be used to determine the cause of symptoms or rule out other conditions. For example, laboratory tests may be used to determine if you have the genetic disorder alpha-1-antitrypsin (AAt) deficiency, which may be the cause of some cases of COPD.