Lung function calculation has emerged as an important way in which to share meaningful personal health information with patients. Spirometry tests measure pulmonary function, providing information on how well the lungs are taking in air, letting it go and circulating oxygen in the body, according to the National Institutes of Health. A patient tends not to understand the significance of this test result when conveyed in traditional form---as a percentage of normal lung function for a person of a given age. This is where calculating lung age comes in handy, as it provides a meaningful illustration to a patient of the age of his lungs compared to non-smokers.
Visit your doctor to have a spirometry test performed or purchase a hand-held spirometer for at-home use. The test consists of either sitting in a clear enclosure and breathing into a mouthpiece or simply breathing nitrogen or helium gas through a tube for a period of time. You may experience shortness of breath or lightheadedness, but no other side effects should occur and completing the test takes little time.
Obtain the results of the test from your doctor or at-home testing device. This will be given as a percentage and based on various factors such as your age and gender. Results close to 100 per cent are best, with those falling at 80 per cent or above considered normal.
Calculate your lung age based on the results of your test. The formula to calculate predicted results for a given age is below---one for males and one for females. Use this same formula to calculate lung age by simply plugging the results of the spirometry test into this same equation and solving for age.
Males: FEV1 = 0.0414 x height (cm) -- 0.0244 x age (yr) -- 3.59
Females: FEV1 = 0.0342 x height (cm) -- 0.0255 x age (yr) -- 1.578
Use a hand-held home spirometer to take regular readings on your lung function, but continue to visit your physician regularly to ensure the most accurate results possible.