What is the Difference Between Peak Flow and Spirometry

The key difference between peak flow and spirometry is that peak flow is a lung test that measures the force with which a person expels air from their lungs, while spirometry is a lung test that measures the amount of air inhaled and exhaled as well as the speed of exhalation.

Peak flow and spirometry are two different tests that help to diagnose lung health. Peak flow measures lung health through a peak flow meter, while spirometry measures lung health through a spirometer. However, spirometry offers a larger range of metrics for diagnosing lung health than a peak flow test.

CONTENTS

1. Overview and Key Difference
2. What is Peak Flow (PEF or PEFR)
3. What is Spirometry
4. Similarities – Peak Flow and Spirometry
5. Peak Flow vs. Spirometry in Tabular Form
6. Summary – Peak Flow vs. Spirometry

What is Peak Flow?

Peak flow is a test to evaluate lung health. It is a quick test to measure the airflow out of the lung. This measure is called peak expiratory flow rate (PEFR) or peak expiratory flow (PEF). A peak flow test is done using a peak flow meter and is mostly performed for people who suffer from asthma. Peak flow measurements can show the amount and rate of air that can be forcefully breathed out of the lungs.

During this test, people have to blow forcefully into the mouthpiece of a device called a PF meter. A peak flow meter is a small handheld device made of plastic. Later, a doctor is able to note the peak flow zones in the meter, such as green (this is the zone people should be in every day), yellow (this zone is a sign of large airways which are starting to narrow) and red (severe narrowing of the large airways). Peak flow tests can also be used to assess other lung problems, such as emphysema and chronic bronchitis. Furthermore, the risks associated with this test may include feeling dizzy or shortness of breath due to taking in deep breaths during the procedure and triggering coughing or wheezing.

What is Spirometry?

Spirometry is a lung test that measures the amount of air inhaled and exhaled as well as the speed of exhalation. This test is performed using a spirometer. Spirometry tests work by measuring the airflow in and out of the lungs. To take a spirometry measurement, people should sit and breathe into a small machine or device called a spirometer. This device records the amount of air people breathe in and out as well as the speed of breath.

Generally, doctors use spirometry tests to diagnose medical conditions such as COPD, asthma, restrictive lung disease (interstitial pulmonary fibrosis), and other disorders affecting the function of the lung. The risks associated with this test may include feeling dizzy or experiencing shortness of breath after the test, severe breathing problems, an increase in existing hypotension, and potential indirect infection.

What are the Similarities Between Peak Flow and Spirometry?

• Peak flow and spirometry are two different tests performed to diagnose lung health.
• Both tests are parts of the regular pulmonary function tests.
• They measure the air volume.
• Both tests can be used to diagnose asthma.
• They have unintended complications or risks.

What is the Difference Between Peak Flow and Spirometry?

Peak flow is a lung test that measures the force with which a person expels air from their lungs, while spirometry is a lung test that measures the amount of air inhaled and exhaled as well as the speed of exhalation. Thus, this is the key difference between peak flow and spirometry. Furthermore, peak flow measures lung health through a peak flow meter, while spirometry measures lung health through a spirometer.

The following table summarizes the difference between peak flow and spirometry.

Summary – Peak Flow vs. Spirometry

Pulmonary function testing is the complete evaluation of the respiratory system. This testing procedure includes patient medical history, physical examinations, and tests of pulmonary function. Pulmonary function tests (PFTs) are noninvasive tests measuring how well the lungs are working. Peak flow and spirometry are two pulmonary function tests to diagnose lung health. Peak flow measures the ability of people to push air out of their lungs, while spirometry measures the amount of air inhaled and exhaled as well as the speed of exhalation. So, this summarizes the difference between peak flow and spirometry.

Reference:

1. “Peak Flow Test.” NHS Choices.
2. “Spirometry.” American Lung Association.

Image Courtesy:

1. “Peak flow meter Philips Respironics PersonalBest 2019-11-29 5272” By Salicyna – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Handheld spirometer” By Cosmed – Own work (CC BY-SA 3.0) via Commons Wikimedia