CTS generally develops between the ages of 30 and 60 and is more common in women, with a female to male ratio of 3:1. Although there are many possible causes, the cause is unknown in most people. There is some evidence that people who develop CTS have a smaller carpal tunnel, explaining why it may run in some families. Other possible causes include:
- Obesity – good predictor of developing CTS
- Arthritis – inflammatory or osteoarthritis of surrounding joints
- Pregnancy – usually resolves after delivery
- Diabetes or a family history of diabetes
- Trauma – recent or old
- Increased activity, including sport or work
- Other medical conditions – underactive thyroid, kidney disease