The pulmonary function test measures how your lungs are working. It measures how much air you breathe out and how long it takes to empty your lungs, plus other measurements to diagnose lung conditions such as asthma and chronic obstructive pulmonary disease (COPD). The same test may be repeated after a breathing treatment.

Before your procedure:

  • Do not smoke for 24 hours.
  • Do not take your breathing medication 6 hours before the test.
  • Do not eat or drink for 2 hours before the test.
  • Do not drink caffeinated beverages 12 hours before the test.
  • Let your technician know if you are experiencing:
    • Pain, especially in your chest, arm or jaw
    • Sore throat or sore mouth
    • Dizziness or fatigue
    • Unusual shortness of breath

During your procedure:

  • The technician will explain the test.
  • You may be sitting on a chair and breath through a mouth piece with a nose clip on. The mouth piece allows you to breath through a machine.
  • For some tests, you may be asked to sit in a clear Plexiglass® breathing chamber.
  • You will be asked to perform various breathing maneuvers. It is very important to follow the instructions at all times.

After your procedure:

  • You can resume your normal activity.
  • You can resume your regular medications. If you are taking a bronchodilator, you may be asked not to take it for up to four hours if one was given during the test.
  • The doctor will discuss the results with you by telephone or at your next office visit.