The carpal tunnel is a narrow passageway within the wrist surrounded by bones and ligaments. The median nerve and the tendons that move the fingers run through the carpal tunnel to the hand. Carpal tunnel syndrome is the result of compression of the median nerve, resulting in the classic symptoms of numbness, pain and weakness.
Carpal tunnel syndrome may be caused by any of a number of factors that reduce the space inside the carpal tunnel. These include:
- Trauma or injury to the wrist.
- Over-use of the hands (for example, participating in work or sporting activities that involve long periods of repetitive movements , such as computer work, assembly line work, construction work, gardening or golfing).
- Fluid retention (for example, as a consequence of pregnancy).
- Inflammation of the tissues (for example due to rheumatoid arthritis).
Low levels of vitamin B6 may also be associated with carpal tunnel syndrome.
Women are more likely to experience carpal tunnel syndrome than men, and are especially susceptible after menopause (due to hormonal changes) and during pregnancy (due to fluid retention).
Other risk factors associated with carpal tunnel syndrome include having a small carpal tunnel, having a family history of the condition, being obese, and suffering from diabetes, thyroid disorders or rheumatoid arthritis.