Aging & Health A to Z
Diagnosis & Tests
Your healthcare provider will take your medical history and do a physical examination. Your provider will probably want to test further for COPD if you have a history of smoking and chronic wheezing, or if you commonly cough up mucus. 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 how fast your lungs empty as you breathe into a machine. Spirograms help determine whether you have COPD and how advanced your illness is. A healthcare provider will ask you to blow into a tube and exhale as fast and completely as you can.
The results of the test will give you a measurement called an “FEV1”. FEV1 is the amount of air that you can forcefully exhale in one second. In healthy lungs, about 70% of the air in your lungs comes out in the first second of exhaling. 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 provider 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 in older people, asthma and COPD can have very similar symptoms and are hard to tell apart. It may be more likely that you have asthma instead of COPD if your lung function is normal during periods where you don’t have symptoms, if your symptoms get worse at night, or if your breathing problems are brought on by identifiable triggers, such as exercise or allergens.
When checking for COPD, your healthcare provider 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 blood gases (the levels of oxygen and carbon dioxide in your blood)
- Exercise tests to observe how breathless you become when you are physically active
- A culture test of the mucus that you produce when you cough
- In certain circumstances, a blood test for genetic causes of COPD
Updated: October 2017
Posted: March 2012