Home Lung Function Test
How It Feels
Breathing in and out very quickly during
these tests may make you feel lightheaded or may make you cough. If you feel
like you are going to pass out, stop the test.
There are no significant risks linked with
measuring peak expiratory flow (PEF). Breathing in and out very quickly during
the test may make you feel lightheaded or may make you cough. If you feel
lightheaded, stop the test.
A home lung function test uses a
peak flow meter or a home spirometer to monitor and evaluate any breathing problems you may have
on a day-to-day basis. A peak flow meter allows you to measure your
peak expiratory flow (PEF). PEF measures how fast you
can exhale using the greatest effort. A home spirometer allows you to measure your forced expiratory volume at 1 second (FEV1). Results from these tests can be compared to
monitor the progression of disease or help measure your response to medical
treatment for a long-term (chronic) lung disease, such as
Peak flows are compared to charts
that list normal values based on age, sex, race, and height. They also can be
compared with your personal best measurement. Check with your doctor or read
the information included with your peak flow meter to find your normal range,
which will vary depending on the type of breathing problems you may have. If
you find abnormal results on any of the tests, discuss them with your
- Normally, peak flows vary slightly throughout the day. They are
usually lower in the morning and higher in the afternoon.
- A person with poorly controlled asthma may have peak flows that
vary more widely throughout the day.
What Affects the Test
The accuracy of peak flow
monitoring depends on your effort during the test. Results will be inaccurate
if you do not follow directions or do not give your best effort during testing.
The following factors also may affect the results of peak flow
- Using medicine that expands the airways in the
lungs within 4 hours before the test may improve the test results.
sedatives before the test may worsen test
- People who have pain while breathing may not be able to breathe
normally. So the results of their tests may be misleading.