Some people have less room in their carpal tunnel than others and are at an elevated risk for carpal tunnel syndrome. Certain health conditions like diabetes, thyroid disorders, and rheumatoid arthritis can also contribute to carpal tunnel syndrome. 

One of the most thought-of causes is repetitive hand and wrist movements. People who work with computers often develop carpal tunnel syndrome, as do those who work on assembly lines, though there is debate over whether repeated movements cause the syndrome. Dislocations of the joint and fractures can also cause narrowing of the carpal tunnel.

Other bodily influences can cause carpal tunnel syndrome as well. Pregnancy can be a leading factor because the hormones produced can cause swelling in various areas of the body, including the wrist. Other hormonal changes, like those in premenstrual syndrome and menopause, may also play a role in the development of the syndrome.