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Home Lung Function Test

A home lung function test uses a peak flow meter camera.gif 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.

Why It Is Done

Testing your peak expiratory flow (PEF) or your forced expiratory volume at 1 second (FEV1) at home may help:

  • Measure how well your lungs are working if you have a long-term (chronic) lung disease, such as asthma.
  • Guide the treatment and monitor the effectiveness of treatment for asthma. Peak expiratory flow monitoring provides information to help people with asthma make better treatment decisions.
  • Monitor your lung function if you are regularly exposed to substances at work that can damage your lungs (occupational asthma).
  • Monitor for early signs of rejection if you have had a lung transplant.

How To Prepare

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 sit up straight or 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.

WebMD Medical Reference from Healthwise

Last Updated: November 28, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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