COPD is commonly misdiagnosed – former smokers are often told they have COPD when in reality they have another less common lung condition. Likewise, many persons who truly do have COPD aren't diagnosed until the disease is far advanced and interventions are less effective.
If you have symptoms of COPD and a history of exposure to lung irritants — especially cigarette smoke — your doctor may recommend these tests:
- Pulmonary function tests. Spirometry is the most common lung function test. During this test, you'll be asked to blow into a large tube connected to a spirometer. This machine measures how much air your lungs can hold and how fast you can blow the air out of your lungs. Spirometry can detect COPD even before you have symptoms of the disease. It can also be used to track the progression of disease and to monitor how well treatment is working.
- 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 your lungs can help detect emphysema and help determine if you might benefit from surgery for COPD. CT scans can also be used to screen for lung cancer, which is more common among people with COPD than it is among those who smoked but didn't develop COPD.
- Arterial blood gas analysis. This blood test measures how well your lungs are bringing oxygen into your blood and removing carbon dioxide.