How to Calculate Lung Age
What is Lung Age?
Lung age estimates the age of your lungs from FEV1 spirometry, comparing actual function to predicted function for different ages. Used in smoking cessation — telling a smoker their lungs are 10 years older is more motivating than quoting FEV1%.
Step-by-Step Guide
- 1Predicted FEV1 by sex, age, height (Quanjer equations)
- 2Lung age: find the age at which predicted FEV1 equals actual FEV1
Worked Examples
Input
FEV1=2.8L · predicted for age 40 is 3.5L (matches 55-yr prediction)
Result
Lung age ≈ 55 (15 years older than actual)
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