Nov 26, 2025 · The FEV1/FVC ratio measures how much air you can exhale in one second compared to a full breath. It helps determine if your lung condition is restrictive or obstructive and its severity.

The FEV1/FVC ratio, also called modified Tiffeneau-Pinelli index, [1] is a calculated ratio used in the diagnosis of obstructive and restrictive lung disease. [2][3] It represents the proportion of a person's …

Obstruction is defined as FEV1/FVC ratio below the lower limits of normal. The rule of thumb is if FEV1/FVC is down 10 or more from the predicted value. Restriction: Spirometry with a low FVC (less …

Mar 15, 2020 · A decreased FEV 1 /FVC ratio is used to define the presence of obstruction. A bronchodilator may be administered to assess responsiveness if an obstructive defect is present.

Jul 1, 2018 · FEV1/FVC: the ratio of FEV1 to FVC expressed as a percentage. Values of FEV1 and FVC are expressed as a percentage of the predicted normal for a person of the same sex, age and height.

Often, doctors use the FVC and FEV1 ratios to figure out the specific type of lung disease. For example, when FEV1 values make up less than 80% of the FVC, an obstructive lung disease is likely present. …

The FEV1/FVC ratio calculator allows you to compute the real-life Tiffneau index and predict the possible result based on your patient's age and height.

Our step-by-step guide to understanding spirometry results: here is what you need to know about FEV1, FVC, and FEV1/FVC ratio.

May 13, 2025 · The FEV1/FVC Ratio measures the proportion of a person’s lung capacity that can be exhaled in the first second of a deep exhale. In healthy adults, the normal FEV1/FVC ratio typically …

The FEV1/FVC ratio is typically expressed as a percentage (such as 75%). Nearly three-fourths of lung volume can normally be exhaled during the first second of the spirometry test.