Studies that have followed thousands of adults for years show that the air you can force out of your chest in one second tracks your risk of dying of any cause, and of heart disease in particular.
Yet most people have never had it measured, or know what their number means.
The measurement is called FEV1, forced expiratory volume in one second. Alongside FVC (forced vital capacity, the total air you can push out after a full inhale), it forms the core of spirometry.
Spirometry is a simple in-office breathing test used by the National Heart, Lung, and Blood Institute (NHLBI) to diagnose asthma, COPD and other lung conditions.
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Where the normal ranges come from
Lung function follows a predictable arc. Lungs finish maturing in the early twenties, and after about age 25 FEV1 declines 1 to 2 percent per year, according to the American Lung Association.
Forced vital capacity drops by about 0.2 liters per decade even in adults who have never smoked.
Because the healthy range depends heavily on age, sex, height and ancestry, your spirometry result is always compared to a predicted value for someone your size.
The clinical benchmark used in pulmonary function labs is straightforward. Normal spirometry is an FEV1/FVC ratio above 0.70, with both FEV1 and FVC above 80 percent of the predicted value.
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Anything below that flags a possible obstructive or restrictive lung condition and calls for a closer look.
Rough FEV1 ranges by age and sex
The figures below are approximate ranges published by device maker Spirometry.com for a healthy 175 cm man and a healthy 160 cm woman.
Actual predicted values are calculated with the international GLI-2022 reference equations recommended by the European Respiratory Society and American Thoracic Society, and depend on your exact height, age and ancestry.
Age group Also read: How eating cinnamon every day may affect your blood sugar and cholesterol | Men FEV1 (liters) | Women FEV1 (liters) |
|---|---|---|
20-40 years | 3.5-4.5 Also read: On Ozempic or Wegovy? Data shows your daily steps may be dropping without you knowing | 2.5-3.5 |
60+ years | 2.5-3.5 | 1.5-2.5 Also read: Cycling vs. running: which is better for your heart, joints and longevity? |
Only a clinician using standardized reference equations can tell you your actual predicted value and whether you sit above or below the 80 percent threshold.
Why the number matters beyond your lungs
FEV1 is not just a lung metric. The PLATINO cohort study tracked roughly 3,000 adults across three Latin American cities for five to nine years.
Each additional liter of FEV1 was linked to a 38 percent lower risk of dying of any cause and a 62 percent lower risk of cardiovascular death.
FEV1 stayed a significant mortality predictor after the researchers adjusted for other risk factors, and it outperformed FVC.
That does not mean a spirometry test itself improves your prognosis. It means a low FEV1 is a signal that something upstream, in the lungs, heart or overall physical reserve, deserves attention.
Who should actually get tested
Anyone with a chronic cough, wheeze, shortness of breath or sputum production should ask a doctor about spirometry. These are also the early warning signs of COPD that most people brush off as normal until the disease is well established.
The US Preventive Services Task Force recommends against routine screening in adults with no respiratory symptoms, giving it a grade D and citing no clear health benefit from early detection in that group.
If any of the symptoms above persist for more than a few weeks, ask your doctor about a spirometry test. It takes a few minutes and involves several forced breaths into a tube attached to a machine called a spirometer.
This article is made and published by Jesper Bengtson, who may have used AI in the preparation.