Lung Function Tests

Pulmonary Function Tests

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

• Using medicine that expands the lungs' airways within 4 hours of the test.
• Using sedatives before the test.
• Eating food or drinks that contain caffeine before the test.
• Not being able to breathe normally because of pain.
• Pregnancy, obesity, or an enlarged stomach (after a large meal, for example).
• Not being able to follow instructions and give some effort to the tests.

Go to previous section	Go to top of page	Go to next section
Author:	Maria G. Essig, MS, ELS	Last Updated: July 3, 2007
Medical Review:	Caroline S. Rhoads, MD - Internal Medicine Robert L. Cowie, MB, FCP(SA), MD, MSc, MFOM - Pulmonology
© 1995-2008 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.