Respiratory function measurements in a cohort of medical students: a ten-year follow-up.

A cohort of medical students first seen in 1962 has now been examined for a third time. The prevalence of symptoms of cough, phlegm, and breathlessness among them has remained low, and smoking habits have been light in comparison with those of the general population. Results of the three successive sets of measurements of lung function indicate that, in general, optimum values were reached in the early 20s, with little further change up to age 29. There was some evidence of reduced ventilatory capacity in subjects with histories of acute chest illnesses.