Understanding your values

An interactive guide to spirometry values for adults with COPD or asthma. Tap a value to see what it means and how it changes with disease.

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FEV1 Forced Expiratory Volume in 1 second

How much air you can forcefully exhale in the first second. The most sensitive single marker for obstructive airway disease.

Typical pattern

FEV1/FVC persistently below 70%. FEV1 around 80% of predicted. Reversibility limited.

How to interpret

How much air you can forcefully exhale in the first second. The most sensitive single marker for obstructive airway disease.

This guide is educational. Always discuss your results with a qualified healthcare professional.