FEV1 and PFT

[Duchess47]

Can you please explain what these tests mean and what the normal numbers should be together.  I am 48 y.o. female 5'1" and 120lbs.  Sometimes my PFT is 379 and other times it is over 400.  I guess this is normal for my stats. But the FEV1 numbers I do not understand.  Thank you

[National Jewish]

A peak flow meter is a small, hand-held device that measures how fast you can blow out air after you have taken in as deep a breath as possible.  This number is the peak expiratory flow (PEF).  It shows how well your lungs are working and the amount of obstruction in your lungs.  The range of normal peak flow numbers is based upon age, gender, and height.  Your normal range would be 365 to 535.  So your numbers are within your normal range.  Since this normal range is an average with some people normally being on the higher end and other people normally being on the lower end, it is best to determine your personal best peak flow.  Then this number is used to determine your color zones.  These zones are helpful to monitor the amount of obstruction.  Sometimes peak flow numbers will drop up to a day before symptoms start.  Please read our peak flow monitoring information at http://www.nationaljewish.org/disease-info/diseases/asthma/living/tools/peak/index.aspx to learn more.

Pulmonary function tests (PFTs) are a variety of breathing tests that provide detailed information about how your lungs are working.  One of these breathing tests is the forced expiratory volume after 1 second (FEV1).  This is the amount of air blown out in the first second.  The normal FEV1 should be 75% of predicted.  When it is below 75% of predicted this is the amount of obstruction in your lungs.  FEV1 is the number most commonly monitored in people with asthma.  A low FEV1 is seen with asthma and COPD.  The FEV1 can be low while the peak flow is in the normal range, because the peak flow does not measure changes in the small airways.

[starion]

PFT is generally used to mean "Pulmonary Function Test," which is a test that is conducted at a doctor's office or medical clinic, using specialized equipment & a trained technician.  The test involves breathing into a machine & produces various numbers which are recorded & interpreted, and often reviewed by a physician.  Included in these numbers would be the FEV1, "Forced Expiratory Volume" in 1st second after a full inhalation (in other words, how much air can you blow out in the 1st second after you have a full inhalation).  This number is often expressed in liters and a % of "normal," comparing the patient to health individuals of the same height, age & gender.

Are you referring to peak flow readings?  FEV1 readings from a device like a Piko-1 meter? Other numbers?

Generally, it's useful to track your personal readings for a period of time & compare them to you prior readings to establish what is YOUR normal & personal best.  Your doctor's office should be able to provide you with further guidance.

Here's a page for more info which you may find helpful.

http://nationaljewish.org/disease-info/diseases/asthma/living/tools/action/index.aspx

Good luck!  Starion

[Duchess47]

Thank you for your post.  I was in fact referring to a peak flow meter.

[Duchess47]

Thank you for clearing this upf for me.  I guess it's the FEV1 that is confusing to me.  When I think my PEF is great I really don't understand the FEV1 reading which is  3.09 or sometimes less.  What does this number represent.

Thanks again