This cross-sectional study was designed considering disagreements on the normal range of Median Nerve Cross-Sectional Area (MNCSA) and its association with age.

In this cross-sectional descriptive study, the upper limbs of 98 healthy subjects (46 men and 52 women) were assessed bilaterally by sonography, and MNCSA was measured at the distal wrist crease.

Mean MNCSA values for subjects older and younger than 40 were 11.25 mm² and 10.21 mm², respectively. The results showed that the MNCSA significantly increased after 40 years of age.

According to the present study's findings, advances in age can increase the MNCSA and affect the diagnostic accuracy of MNCSA measurement in CTS diagnosis.