Want more iVillage? Sign up for our
Newsletters
Lung Function Tests - Results
About this test
Lung function tests (also called pulmonary function tests, or PFTs) check how well your lungs work. The normal value ranges for lung function tests will be adjusted for your age, height, sex, and sometimes weight and race. Results are often expressed in terms of a percentage of the expected value. Most test results are available right away.
Normal
Test results are within the normal ranges for a person with healthy lungs.
Abnormal
Test results are outside of the normal range for a person with healthy lungs. This may mean that some kind of lung disease is present. There are two main types of lung disease that can be found with lung function tests: obstructive and restrictive.
Obstructive
In obstructive lung conditions, the airways are narrowed, usually causing an increase in the time it takes to empty the lungs. Obstructive lung disease can be caused by conditions such as emphysema, bronchitis, infection (which produces inflammation), and asthma.
| Lung function test | Result as predicted for age, height, sex, weight, or race |
|---|---|
Forced vital capacity (FVC) | Normal or lower than predicted value |
Forced expiratory volume (FEV1) | Lower |
FEV1 divided by FVC | Lower |
Forced expiratory flow 25% to 75% | Lower |
Lower | |
Maximum voluntary ventilation (MVV) | Lower |
Slow vital capacity (SVC) | Normal or lower |
Normal or higher | |
Functional residual capacity (FRC) | Higher |
Higher | |
Expiratory reserve volume (ERV) | Normal or lower |
RV divided by TLC ratio | Higher |
FEV1 often increases after using medicine that expands the airways in people with reversible obstructive disease like asthma.
Restrictive
In restrictive lung conditions, there is a loss of lung tissue, a decrease in the lungs' ability to expand, or a decrease in the lungs' ability to transfer oxygen to the blood (or carbon dioxide out of the blood). Restrictive lung disease can be caused by conditions such as pneumonia, lung cancer, scleroderma, pulmonary fibrosis, sarcoidosis, or multiple sclerosis. Other restrictive conditions include some chest injuries, being very overweight (obesity), pregnancy, and loss of lung tissue due to surgery.
| Lung function test | Result as predicted for age, height, sex, weight, or race |
|---|---|
Forced vital capacity (FVC) | Lower than predicted value |
Forced expiratory volume (FEV1) | Normal or lower |
FEV1 divided by FVC | Normal or higher |
Forced expiratory flow 25% to 75% | Normal or lower |
Normal or lower | |
Maximum voluntary ventilation (MVV) | Normal or lower |
Slow vital capacity (SVC) | Lower |
Lower | |
Functional residual capacity (FRC) | Normal or lower |
Normal, lower, or higher | |
Expiratory reserve volume (ERV) | Normal or lower |
RV divided by TLC ratio | Normal or higher |
| By: | Healthwise Staff | Last Revised: April 28, 2011 |
| Medical Review: | E. Gregory Thompson, MD - Internal Medicine Mark A. Rasmus, MD - Pulmonology, Critical Care Medicine, Sleep Medicine | |
© 1995-2011 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, Incorporated 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.
Welcome to Care Circle, an exclusive tool to help you take care of yourself and your loved ones. Here's how it works:
- Create profiles for yourself and your loved ones.
- Select the topics and conditions that interest each of you.
- Get customized news updates, original content, tools, and expert advice for each Care Circle member delivered directly to your personalized homepage.
The information you input is strictly private; you choose who has access to your Care Circle.
How do I add myself or someone else to my care circle?
Click on "Add someone." Fill out the short profile. Choose an avatar. Select the topics and conditions that interest this person from the pulldown menu. You can select as many as you want, but you must choose at least one. Click on "Add Someone" again. You should start getting updates immediately.
How do I save content to my Care Circle?
Click on "Manage My Care Circle." Select the tab of the person for whom you're saving content. Put your cursor over the piece of content that you want to save; a disk icon will appear in the righthand corner. Click on the disk and the piece of content will be moved to a save folder.
How do I add additional topics and conditions for someone in my Care Circle?
Click on "Manage My Care Circle." Select the tab for the person whose preferences you'd like to update. Under "Add More to Follow," select additional topics and conditions.
How do I delete topics and conditions for someone in my Care Circle?
Click on "Manage My Care Circle." Select the tab for the person whose preferences you'd like to update. Under "Follows," scroll over the topic or condition you want to delete. An "X" should appear on the righthand side. Click on the "X" and the topic or condition will be deleted from the list.
To manage your Care Circle, Please
Sign In.
from
- 9 nastiest things in your supermarket
- Facebook is now fueling organ donations
- Military women and suicide: Home safe but not sound
- Still in gear: Injuries don’t stop veterans on 100-day bike trek
- Ask Jenna: I've hit a weight loss plateau. What do I do?
- He poses in a tutu to laugh in face of wife's cancer
The iVillage Network