You should be retested in three to five years. Your test results may be normal now, but you can still become abnormal later. Smoking attracts inflammatory cells that release enzymes that digest the lung. It may be a few years before enough digestion has taken place to be detected by spirometry. In addition, smoking puts you at risk for many diseases, including cancers of the mouth, throat, esophagus, stomach, and bladder, heart disease, hypertension, stroke, peripheral vascular disease and leukemia.
Smoking also causes premature wrinkles.
Amazingly, spirometry results predict sickness and death from all causes, even though it is a lung test. Abnormal spirometry results predict increased risk for premature death, heart disease, lung cancer, stroke, and even premature wrinkling. You should talk to your doctor. What you can do to make your lungs better will depend on why your numbers are abnormal. Obviously, stop smoking, if you smoke.