Inside your wrist there is a small gap called the carpal tunnel, through which the median nerve runs from your hand to your forearm. The function of this nerve allows you to feel sensation in almost every finger on your hand. The median nerve also communicates movement signals that allow your thumb to move.
People who frequently use their hands at work, such as typists, data-entry clerks, or musicians can find themselves dealing with symptoms that indicate carpal tunnel syndrome. These symptoms commonly include weakness in the hands, numbness, or tingling. These sensations generally start in the thumb and index and middle fingers. At first, the tingling or numbness come and go at odd times. Over time, these feelings can begin to move up your arm.
It used to be thought that simple overuse of the hands was the cause of carpal tunnel syndrome, but new research is pointing the finger at medical conditions that include diabetes, hypothyroidism, osteoarthritis, and rheumatoid arthritis.
People who develop rheumatoid arthritis in their hands and wrists can develop carpal tunnel syndrome because of the swelling caused by arthritis.
Patients undergoing hemodialysis (dialysis) to control chronic kidney damage develop a buildup of the beta 2-microglobulin protein in their hands. Over time, as this protein builds up, it can lead to CTS.
- Some environmental causes can make people more likely to develop carpal tunnel syndrome. These can include smoking, alcohol abuse, obesity and, in some cases, a high degree of mental stress.
- Pregnant women are at higher risk of developing this condition as well. Some patients have identified family members with the condition, leading medical researchers to consider genetic causes.
- Repetitive hand and wrist movements, especially in cold temperatures, can lead to the development of CTS.
- Medical conditions can cause or increase your risk of developing CTS. Diabetics who develop diabetic neuropathy are at high risk of developing CTS. Roughly 85% of people with Type 1 diabetes have developed CTS.
- Patients suffering from autoimmune diseases can develop CTS. In an autoimmune disease, the patient’s immune system attacks its own tissues. Systemic lupus erythematosus, thyroiditis, and rheumatoid arthritis are among these diseases. Research indicates that CTS caused by autoimmune diseases can be more severe, requiring surgery to correct it. Gout, arthritis, and other diseases that affect bones, joints, and muscles can lead to the development of CTS.
- Other conditions can include injuries, structural abnormalities of the hand, and hormone changes. If you break your wrist, this can cause the carpal tunnel to become too narrow, which can lead to irritation of the median nerve. Some medications can also lead to the development of carpal tunnel syndrome.
If a person at high risk of developing carpal tunnel syndrome exposes his or her hands and wrists to repetitive movements, the risk for carpal tunnel syndrome increases.