FEV₁:FVC Ratio | 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.

FEV₁:FVC Ratio



  • The ratio between the forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC) is also known as the Tiffeneau-Pinelli index. This ratio is used to assess for the fraction of air that the patient is able to expel in the first second,  and a reduced ratio is a sign of obstruction.
      • Normal Range

      • >0.70
  • A reduced FEV₁/FVC ratio (<0.7) is indicative of obstructive pulmonary disease.
    • Causes of Obstructive Disease

    • COPD
    • Asthma
    • Bronchiectasis
    • Cystic fibrosis
    • Bronchiolitis
    • α1-antitripsin deficiency
Last updated on March 10th, 2020