Establishing the diagnosis

In general, a doctor diagnoses COPD by conducting a lung capacity test. The lung capacity test, also called spirometry by the medical profession, is a breathing test that examines if the lungs are working properly. If the lung capacity is much less than normal, it could point to COPD. A lung capacity test or spirometry is a simple, painless and reliable way to diagnose COPD, and takes about 45 minutes.

Sometimes, additional tests are necessary besides spirometry, such as a chest X-ray or CT scan. A CT scan clearly shows abnormalities in the lung tissue. A CT scan is always carried out in a hospital.

Your doctor may also measure how breathing responds to exercise, for example after walking or cycling. X-rays, an exercise test, an allergy test or more extensive spirometry sometimes provides more information about the condition of the lungs.