What is a spirometer?


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  • To monitor a lung disease

  • To monitor the effectiveness of treatment

  • To determine the severity of a lung disease


After taking a deep breath, a person forcefully breathes out into the spirometer as completely and forcefully as possible. The spirometer measures both the amount of air expelled and how quickly the air was expelled from the lungs. The measurements are recorded by the spirometer.

The normal, healthy values measured by the spirometer for the amount of air exhaled vary from person to person. Your results are compared to the average expected in someone of the same age, height, sex, and race, according to the National Heart, Lung, and Blood Institute (NHLBI). However, if the values fall below 80 percent of the average, it may be a sign of lung disease or other airflow obstruction. If a person has abnormal spirometer measurements, he or she may need to have other lung tests to establish a diagnosis.

How often will this test be administered?

In some cases, spirometry may be recommended for individuals with a family history of lung disease and chronic respiratory problems to establish your personal baseline (a comparative measure that is used as your "optimal" measurement of lung function), according to the NHLBI. However, certain high-risk groups, such as smokers, those exposed to occupational irritants, and those with breathing and coughing problems, may be recommended to undergo spirometry on a routine basis, as ordered by their doctors.