Skip to main navigation Skip to main content Skip to footer For Medicare For Providers For Brokers For Employers Español For Individuals & Families: For Individuals & Families Medical Dental Other Supplemental Explore coverage through work How to Buy Health Insurance Types of Dental Insurance Open Enrollment vs. Special Enrollment See all topics Shop for Medicare plans Member Guide Find a Doctor Log in to myCigna
Home Knowledge Center Wellness Library Asthma: Measuring Peak Flow

Asthma: Measuring Peak Flow

Overview

It's important to know how well your lungs are working. One way to do this is by checking your peak flow with a peak flow meter. Your peak flow can tell you if your asthma is staying the same, getting better, or getting worse. It helps you know if you need to take action.

How do you measure your peak expiratory flow?

How do you measure your peak expiratory flow?

Getting started

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 to learn how long 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 the 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 before performing a PEF test. Be sure to sit up or stand up as straight as possible 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.

Measuring your peak flow

Set the meter to its lowest number: Step 1

A child setting a peak flow meter to its lowest number
slide 1 of 6
slide 1 of 6, Set the meter to its lowest number: Step 1,

Put the pointer on the gauge of the peak flow meter to 0 or the lowest number on the meter. In the photo, this is about 50.

Attach the mouthpiece: Step 2

A child attaching a mouthpiece to the peak flow meter
slide 2 of 6
slide 2 of 6, Attach the mouthpiece: Step 2,

Attach the mouthpiece to the peak flow meter. Some meters don't have a separate mouthpiece.

Take a deep breath: Step 3

A child taking a deep breath to get ready to use the peak flow meter
slide 3 of 6
slide 3 of 6, Take a deep breath: Step 3,

While standing, take a deep breath.

Put the mouthpiece in your mouth: Step 4

A child putting the peak flow meter mouthpiece in her mouth
slide 4 of 6
slide 4 of 6, Put the mouthpiece in your mouth: Step 4,

Put the peak flow meter mouthpiece in your mouth, and close your lips tightly around the outside of the mouthpiece. Don't put your tongue inside the mouthpiece.

Breath out hard: Step 5

A child breathing out hard into the peak flow meter
slide 5 of 6
slide 5 of 6, Breath out hard: Step 5,

Breathe out as hard and as fast as you can for 1 or 2 seconds. A hard and fast breath usually produces a "huff" sound.

Check your number: Step 6

A peak expiratory flow result of about 180
slide 6 of 6
slide 6 of 6, Check your number: Step 6,

Check the number on the gauge, and write it down. This is your peak expiratory flow (PEF). In the photo, the PEF is about 180.

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. Learn how we develop our content.

© 1995-2022 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

<cipublic-spinner variant="large"><span>Loading…</span></cipublic-spinner>

Page Footer

I want to...

Get an ID card File a claim View my claims and EOBs Check coverage under my plan See prescription drug list Find an in-network doctor, dentist, or facility Find a form Find 1095-B tax form information View the Cigna Glossary Contact Cigna

Audiences

Individuals and Families Medicare Employers Brokers Providers

Secure Member Sites

myCigna member portal Health Care Provider portal Cigna for Employers Client Resource Portal Cigna for Brokers

Cigna Company Information

About Cigna Company Profile Careers Newsroom Investors Suppliers Third Party Administrators International Evernorth

 Cigna. All rights reserved.

Privacy Legal Product Disclosures Cigna Company Names Customer Rights Accessibility Non-Discrimination Notice [PDF] Language Assistance [PDF] Report Fraud Sitemap

Disclaimer

Individual and family medical and dental insurance plans are insured by Cigna Health and Life Insurance Company (CHLIC), Cigna HealthCare of Arizona, Inc., Cigna HealthCare of Illinois, Inc., and Cigna HealthCare of North Carolina, Inc. Group health insurance and health benefit plans are insured or administered by CHLIC, Connecticut General Life Insurance Company (CGLIC), or their affiliates (see a listing of the legal entities  that insure or administer group HMO, dental HMO, and other products or services in your state). Accidental Injury, Critical Illness, and Hospital Care plans or insurance policies are distributed exclusively by or through operating subsidiaries of Cigna Corporation, are administered by Cigna Health and Life Insurance Company, and are insured by either (i) Cigna Health and Life Insurance Company (Bloomfield, CT); (ii) Life Insurance Company of North America (“LINA”) (Philadelphia, PA); or (iii) New York Life Group Insurance Company of NY (“NYLGICNY”) (New York, NY), formerly known as Cigna Life Insurance Company of New York. The Cigna name, logo, and other Cigna marks are owned by Cigna Intellectual Property, Inc. LINA and NYLGICNY are not affiliates of Cigna.

All insurance policies and group benefit plans contain exclusions and limitations. For availability, costs and complete details of coverage, contact a licensed agent or Cigna sales representative. This website is not intended for residents of New Mexico.

Selecting these links will take you away from Cigna.com to another website, which may be a non-Cigna website. Cigna may not control the content or links of non-Cigna websites. Details