Aging & Health A to Z
Diagnosis & Tests
Your healthcare professional will take your medical history and do a physical examination. If you have a history of smoking and chronic wheezing, or if you commonly cough up mucus, the healthcare professional will probably want to test further for COPD. Lung function tests and perhaps a few other painless procedures are used to confirm a COPD diagnosis.
The best lung function test for COPD is a spirogram. This test measures the amount of air in your lungs and the rate at which your lungs empty as you breathe into a machine. Spirograms help determine whether you have COPD and how advanced your illness is. A healthcare professional will ask you to blow into a tube, exhaling (breathing out) as fast and completely as you can.
The results of the test are expressed in terms of the FEV1, which is the amount of air that you breathe out in the first second when you exhale forcefully. In healthy lungs, about 70% of the air in your lungs comes out in the first second. If you have COPD, you will breathe out less than 70% of the air in your lungs in that time.
Spirometry also measures the maximum amount of air that you can force out in a large breath. This is called the “forced vital capacity” or FVC. The FVC is also lower in people with COPD compared to healthy people who are the same age, sex, and size.
Your healthcare professional will also give you an inhaled medicine called a bronchodilator and then repeat the spirometry tests. If your spirometry scores improve after taking the bronchodilator, you may be suffering from asthma. Sometimes—especially in older people—asthma and COPD can have very similar symptoms and are hard to tell apart.
When checking for COPD, your healthcare professional will also use a stethoscope to listen to your lungs as you breathe in and out. Other tests that you may have include:
- A chest x-ray
- CT scan
- A blood test to measure the levels of oxygen and carbon dioxide in your blood (blood gases)
- Exercise tests to observe how breathless you become when you are physically active
- A culture test of mucus that you produce when you cough
- In certain circumstances, a blood test for genetic causes of COPD
Updated: March 2012
Posted: March 2012