Home > Patients & Visitors > Health Library > Home Lung Function 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. A home spirometer allows you to measure your forced expiratory volume at 1 second (FEV1).
If you have a lung disease, such as asthma, your doctor may test your peak inspiratory flow (PIF) and peak expiratory flow (PEF) to measure the amount of air you can inhale and exhale. This is part of a more complete lung function test.
Testing your peak expiratory flow (PEF) or your forced expiratory volume at 1 second (FEV1) at home may help:
To perform the peak expiratory flow (PEF) test, you need a peak flow meter. A peak flow meter is an inexpensive handheld device you breathe into as hard and as fast as you can.
Read and follow the instructions included with the peak flow meter. Ask your doctor to show you how to use this device before you use it at home. If you have questions about how to use a peak flow meter or how to read the results, talk with your doctor.
If you use medicine to help with breathing (such as for asthma), talk to your doctor about the amount of time you should wait to test your lung function after taking your medicine. You may need to wait a few hours after taking the medicine to do a lung function test. Or your doctor may recommend that you test your lung function in the morning before you take your medicine.
Avoid eating a heavy meal for about 3 hours before performing a PEF test. Be sure to stand up to help you take as large a breath as you can. Use the same position every time you test your PEF. Peak flow monitoring relies on your trying as hard as you can. For accurate results, be sure to give the test your best effort every time.
Before you begin to test your peak expiratory flow (PEF), remove any gum or food you may have in your mouth. Follow these steps to use your peak flow meter:
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 much air you breathe out when you try your hardest. 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 asthma.
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 doctor.
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 monitoring:
Other Works Consulted
Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Holcroft CA, et al. (2003). Measurement characteristics of peak expiratory flow. Chest, 124(2): 501–510.
National Institutes of Health (2007). National Asthma Education and Prevention Program Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma (NIH Publication No. 08–5846). Available online: http://www.nhlbi.nih.gov/guidelines/asthma/index.htm.
Current as of: February 24, 2020
Author: Healthwise StaffMedical Review: E. Gregory Thompson, MD - Internal MedicineAdam Husney, MD - Family MedicineElizabeth T. Russo, MD - Internal Medicine
Current as of: February 24, 2020
Author: Healthwise Staff
Medical Review:E. Gregory Thompson, MD - Internal Medicine & Adam Husney, MD - Family Medicine & Elizabeth T. Russo, MD - Internal Medicine
To learn more about Healthwise, visit Healthwise.org.
© 1995-2020 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.
You'll find Decision Points to help you answer questions about:
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups and pregnancy.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.