When doing a lung function test at home, a Peak Flow Meter or Home Spirometer is used to evaluate daily breathing problems; Peak Expiratory Flow (PEF) measures peak exhalation flow rate, Home version pulmonary energy meter measures Forced Expiratory Volume at 1 Second (FEV1)


If you have a lung disease, such as Asthma, your doctor may detect Peak Inspiratory Flow (PIF) or spikes to measure the amount of air a patient can inhale and dissipate as part of a complete lung function test.

Why do I need to test lung function at home?

Measuring peak exhalation rate at home or exhaling hard for 1 second helps with the following:

  • If you have chronic lung diseases, such as asthma, doing these two tests can help you understand the condition of lung function.
  • The results can help physicians diagnose the condition, determine the treatment, and monitor the effect of asthma.
  • If working environments are often exposing you to substances that can damage your lungs, these two tests can help to understand the condition of lung function.
  • If a lung transplant has been performed, these two tests monitor the initial signs of rejection.

Before Testing

The peak exhalation rate is lowest in the morning and the highest in the afternoon. If you measure only once a day, get up early in the morning and take Bronchodilator Medicine before measurement. In addition, patients with intermittent or mildly persistent asthma may not be required to detect peak exhalation rates every day, but checking for peak exhalation rates for some time may help to control asthma if symptoms occur.

Process of Lung function Test

What should you prepared in advance?

To test peak exhalation flow, you first need to prepare a peak exhalation flow meter, follow the peak exhalation flow meter guidelines and follow the test procedure below, or ask your doctor to demonstrate how to use it before use. If you have any concerns about peak exhalation flowmeter or measurement results, consult a physician.

In addition, do not eat undigestible meals 3 hours before the peak exhalation rate is detected. Please stand up and hold the same position to help smooth breathing flow, peak exhalation meter requires the subject to inhale as hard as possible. In order to make the test results more accurate, every steps for the test needs to be done.

What are the steps for Lung Function Test

Remove food from your mouth, such as chewing gum, before starting to detect peak exhalation rates, and follow these steps:

  • See the pointer on the peak exhalation flowmeter to zero.
  • Attach the blowout to the peak exhalation meter.
  • Stand straight or sit back so that you can breathe deeply.
  • Maintain the same position every time you measure whether you are standing or sitting.
  • Take a deep breath, put the peak exhaler in your mouth, and your lips should tightly wrap the mouth.
  • Do not stick your tongue into the mouth.
  • Exhale as fast as possible without blowing more than 1 second.
  • View the values on the instrument.
  • Before exhaling the second time, return the pointer to zero.
  • Do a total of 3 tests of each exhalation to record the test value. If you cough or make a mistake during the test, please remeasure.
  • After completing the last 3 tests, please note the highest value in the log book.

After Testing

Consult your doctor or read the information that comes with your peak exhaler to understand the normal values, which vary depending on breathing problems. If you think your test results are abnormal, ask your doctor for help.

Results after the test

Combining spike exhalation rate and 1-second hard exhalation, physicians can use these results to monitor the progress of the disease or control the efficacy of chronic lung diseases, such as asthma, to help with the treatment. Regular home users may define differently depending on the laboratory and hospital. If you have concerns about the test results, consult your doctor for more information.

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