Part UT Health San Antonio
UT Health San AntonioUT Health San Antonio

UTSA Part of UT Health San Antonio

Contact Us | 210-450-9000

Menu
  • Find a Provider
  • Services
  • Cancer Types
  • Locations
  • Patient Care
  • Cancer Center
  • MyChart
  • X
  • Conditions
  • Conditions In-depth
  • Procedures
  • Wellness Centers
  • Natural & Alternative
  • Drug Info
  • Procedure Animations
  • Wellness Videos
Symptom CheckerQuick Nav
 
Health Library Home>Procedure & Surgery Fact Sheets>Article

Pulmonary Function Tests

(PFT)

by Editorial Staff and Contributors
Definition
Reasons for Test
Possible Complications
What to Expect
Results
Call Your Doctor

Definition

Pulmonary function tests (PFTs) are a group of tests that show how well your lungs are working. PFTs may measure:

  • How much air you can blow out
  • How much air your lungs can hold at different times during the breathing cycle
  • How fast you are blowing air out
  • How well gas is being transferred from your lungs into your blood

Respiratory System
nucleus factsheet image

Copyright © Nucleus Medical Media, Inc.

Reasons for Test

PFTs may be used to help diagnose or check the affect of lung conditions or diseases, such as:

  • Asthma
  • Allergies
  • Trouble breathing after injury to chest or surgery
  • Emphysema
  • Chronic bronchitis
  • Cystic fibrosis
  • Alpha-1 antitrypsin deficiency
  • Asbestosis
  • Sarcoidosis
  • Scleroderma
  • Problems that make it hard to move air in and out of the lungs from scoliosis, tumors, inflammation, or scarring of the lungs
  • Idiopathic pulmonary fibrosis
  • Interstitial lung disease

These tests may also be done to:

  • Show how well a treatment is working
  • Check affect of symptoms, such as coughing, wheezing, and trouble breathing
  • Check how well your lungs are working before or after a surgery
  • Measure a lung problem or muscle weakness

Possible Complications

There are no major problems linked to these tests.

What to Expect

Prior to Test

  • Review your medicine with your doctor. You may need to stop taking some before testing.
  • Do not eat, smoke, or exercise for 4 to 8 hours before testing.
  • Wear loose-fitting clothing.

Description of Test

The exact steps will depend on the reason for the test. In most cases, the procedure will be as follows:

  1. You will be asked to loosen tight clothing, or jewelry. You will need to wear dentures if you have them.
  2. You will sit in a chair. A soft clip will be put on your nose. All of your breathing will need to pass through your mouth.
  3. The doctor will ask you to breathe into a mouthpiece. The mouthpiece is attached to a tool that measure breath.
  4. You will be asked to breathe in and out in different ways.
  5. The team will watch you carefully for dizziness, trouble breathing, or other problems.

You may be given medicine to inhale after certain tests. The tests will then be repeated after the medicine has started to work.

Peak Flow Meter
Lung test peak flow meter

Copyright © Nucleus Medical Media, Inc.

Other steps that may be needed include:

  • A brief period of exercise before the test.
  • A small clip will be attached to your finger. It will measure the amount of oxygen in your blood.
  • A special chemical will be given as a mist. If you have asthma the chemical will cause a spasm in the airway. This is only done under medical care.
  • You may be asked to breathe in small amount of carbon monoxide for 1 minute. It will be followed to see how much gets into your blood. This will show how well oxygen is getting into your blood.

After Test

Rest until you feel able to leave. You may have wheezing, coughing, and/or problems breathing. It will be treated before you leave.

How Long Will It Take?

20 to 45 minutes

Will It Hurt?

The test does not hurt. You may feel some symptoms during or right after testing.

Results

Your doctor will compare the results of your tests with normal values. The results will also be checked with tests you may have already done. Your doctor will discuss the results with you.

Call Your Doctor

After the test, call your doctor if any of the following occurs:

  • Headaches, nausea, muscle aches, lightheadedness, or general ill feeling
  • Shortness of breath or difficulty breathing
  • Wheezing or persistent coughing
  • Chest pain
RESOURCES:

American Lung Association
http://www.lung.org

Family Doctor—American Academy of Family Physicians
http://familydoctor.org

CANADIAN RESOURCES:

COPD Canada
http://www.copdcanada.ca

The Lung Association
http://www.lung.ca

REFERENCES:

Pulmonary function tests. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T900274/Pulmonary-function-tests. Updated March 20, 2019. Accessed December 17, 2019.

Pulmonary Disease, Chronic Obstructive (COPD): Quality of Life. EBSCO Nursing Reference Center website. Available at: http://www.ebscohost.com/nursing/products/nursing-reference-center. Updated December 28, 2018. Accessed December 17, 2019.

Last reviewed December 2019 by EBSCO Medical Review Board Nicole Meregian, PA  Last Updated: 8/7/2020

EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

To send comments or feedback to our Editorial Team regarding the content please email us at healthlibrarysupport@ebsco.com. Our Health Library Support team will respond to your email request within 2 business days.

Copyright ©  EBSCO Information Services
All rights reserved.
Privacy Policy | Editorial Policy
Physicians and care providers of
UT Health San Antonio

8300 Floyd Curl Dr.

San Antonio, TX 78229

210-450-9000

Connect with us
  • Patient Rights and Responsibilities
  • Language Assistance
We make lives better ©

We're a part of UT Health San Antonio, provider of comprehensive health,  dental, &  cancer care,  advanced academics  and  life-saving research.

Web Privacy | Links from websites affiliated with The University of Texas Health Science Center at San Antonio's website (uthscsa.edu) to other websites do not constitute or imply university endorsement of those sites, their content, or products and services associated with those sites. The content on this website is intended to be used for informational purposes only. Health information on this site is not meant to be used to diagnose or treat conditions. Consult a health care provider if you are in need of treatment.