FEV₁ | Lung Function Tests - MedSchool
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Lung Function Tests
Lung Function Tests
Pulmonary function tests including spirometry, flow-volume loops, lung volumes and diffusion capacity can be used to diagnose and grade obstructive or restrictive lung disease.




  • The forced expiratory volume in 1 sec (FEV₁) is the amount of air forcefully exhaled in the first second following a maximal inhalation.
      • Normal Range

      • 80 - 120% predicted
  • Low FEV₁ (<80% predicted) indicates obstructive or restrictive disease, though may also be due to poor expiratory effort.
Last updated on March 10th, 2020