If you are at risk for chronic obstructive pulmonary disease (COPD), your physician may ask you to take a spirometry test. Spirometry does not take long and does not hurt. It measures your breathing ability. For the test, you breathe into a tube attached to a spirometer. The device figures out how much air your lungs can hold and how fast you can inhale and exhale it.

Your physician will compare your test with the typical results of a healthy person of similar height, age, sex, and race. An abnormal reading is any value lower than 80 percent of the predicted value for the individual. You may have COPD if your reading is lower than 70 percent of what is expected.

You should take a spirometry test every year or as often as your physician directs. The results can show how your COPD responds to a certain type of therapy or treatment.