Print this topic

HealthInfo Canterbury

COPD tests & diagnosis

If you or your GP suspect that you have COPD, you may need to have a test called spirometry to see how well your lungs are working. The spirometry test measures how well you can blow air into a machine.

Spirometry testing is easy to do and you can have the test in many places throughout Canterbury. Your GP will refer you to the most convenient place.

Other tests used to assess people with COPD

Pulse oximetry

This is a simple test that measures oxygen levels in your blood using a light probe on your finger. You can have normal or near-normal oxygen levels even if you are short of breath. There is a difference between being short of breath and being short of oxygen.

Chest X-ray

You don't always need to have a chest X-ray to diagnose COPD. But your GP may refer you for one to rule out other conditions.


An ECG is a recording of your heart's electrical activity. Your GP may order this test to rule out heart conditions that can produce symptoms similar to those of COPD. They may also want to know how well your heart is working.

Blood tests

Blood tests are not needed to diagnose COPD. But your doctor may arrange blood tests to rule out other conditions that can cause breathlessness.

On the next page: COPD treatments

Written by HealthInfo clinical advisers. Endorsed by community respiratory physician, Canterbury DHB. Last reviewed May 2017.

See also:

Preparing for your doctor's visit

Page reference: 53518

Review key: HICOP-16602