The median nerve is a nerve in the upper extremity to provide sensation to your thumb, index finger, middle finger, and ring finger. It also provides motor function, meaning your ability to move and have strength in your hand. So it has motor function as well as sensory function in the hand. We're all different anatomically. We all have slight differences in our anatomy and some patients' anatomy is such that they're at an increased risk for developing carpal tunnel syndrome. For instance, they may just have a smaller space available for the median nerve, so they develop carpal tunnel syndrome more easily than someone else might.