Table 1—

Lower limit of normal of various lung function indices expressed as a percentage of the predicted value at two extremes of age#

MalesFemales
25 yrs70 yrs25 yrs70 yrs
FEV181738171
FVC81758172
FEV1 (% FVC)86848786
PEF80757974
FRC70736970
RV59745872
TLC84848080
RV (% TLC)62786578
TL,CO81748073
  • FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; PEF: peak expiratory flow; FRC: functional residual capacity; RV: residual volume; TLC: total lung capacity; TL,CO: transfer factor of the lung for carbon monoxide. #: for males and females of average height (1.74 and 1.66 m, respectively).