Tal Klatchko, D.O.

Pulmonary & Critical Care
Roper-St. Francis Hospital
Charleston, South Carolina

Pulmonary Function Testing

Pulmonary function testing is done to check the function of your lungs. These tests measure how much air and how easily air moves in and out of your lungs.

Purpose of Pulmonary Function Test:

  • Help your doctor diagnose lung disease.
  • Monitor how your lung disease may change over time.
  • Help find what treatment may help you.
  • Check your lungs if general anesthesia is needed for surgery.

Before the Test

  • Do not smoke for 4 to 6 hours before the test.

  • You may eat before the test, but only eat a small meal. If you eat a large meal, it will give you a full stomach. This will decrease your ability to take deep breaths and do the tests well.
  • You’ll get specific instructions if you need to stop using bronchodilators or inhaler medications. You may have to breathe in medication before the test.

During the Test

  • Pulmonary function tests are done in thePulmonary Function Laboratory.

  • The technician will give you specific instructions for each of the tests. For
    example, you may be asked to breathe in as deeply as you can and then blow air out
    as fast as you can. You also may be asked to breathe normally, and then take in as big
    a breath as you can and to hold your breath for several seconds. You will repeat the test several times. Accurate measurements depend on you following the instructions and giving your best effort.
  • A nose clip will be put on your nose so that you breathe through your mouth during the test. If air escapes through your nose, incorrect measurements may occur.
  • You may be given a medicine to inhale. Some tests will then be repeated to see the effect or benefit of the medicine.
  • The breathing exercises may make you tired or short of breath. You will be given rest periods during the test if you need them.
  • The doctor also may take a blood sample to check the amount of oxygen, carbon dioxide or hemoglobin in your blood.

After the Test

  • The results of the test are reported to your doctor. Your doctor will discuss the test results with you.
  • There are no side effects from these tests. You may feel tired and want to rest after the test is over.