Causes of Carpal Tunnel Syndrome
What is the Carpal Tunnel? What are the symptoms? What causes the condition? Learn how to prevent this condition and when to see a doctor.
The Carpal Tunnel is a passageway that runs from the wrist to the hand and carries the median nerve, which supplies feeling to the fingers and provides function of the muscles in the hand.
Symptoms can include: pain in the wrist, pain in the hand, numbness or tingling in the fingers or the feeling that there may be swelling in the fingers or hand (despite no apparent swelling). Over time, numbness can become more severe and a person may lose the inability to feel hot and cold in the hand.
CTS is considered an inflammatory condition caused by stress, injury or trauma. However, it is difficult to pinpoint one singular cause of CTS.
Even though medical and physical conditions may be the initial culprits leading to CTS, certain working conditions may be linked to nerve damage. Work that involves high force or vibration is particularly hazardous, as is repetitive hand and wrist work in cold temperatures.
CTS is a very common feature of diabetic neuropathy, one of the major complications of diabetes. Neuropathy is decreased or distorted nerve function; it particularly affects sensation. Symptoms include numbness, tingling, weakness, and burning sensations, usually starting in the fingers and toes and moving up to the arms and legs. Up to 85% of patients with type 1 diabetes develop CTS.
In autoimmune diseases, the body's immune system abnormally attacks its own tissue, causing widespread inflammation, which, in many cases, affects the carpal tunnel of the hand. Such autoimmune diseases include rheumatoid arthritis, systemic lupus erythematosus, and thyroiditis, which can lead to hypothyroidism.
Abnormalities in the bone, wrist, hand or nerve tunnel could contribute to the development of CTS.
People who have hemodialysis for chronic kidney damage often experience a buildup of a certain type of protein, called beta 2-microglobulin, in the hand. This buildup can result in CTS. The longer the person has been receiving hemodialysis, the greater the risk of CTS. Certain drugs and procedures (particularly a procedure called hemodiafiltration) may be able to reduce microglobulin build-up.
Evidence suggests that about 3% of women and 2% of men will be diagnosed with carpal tunnel syndrome during their lifetime. The condition peaks in women over age 55. Still, determining how many people actually have CTS is very difficult. Many people who report CTS symptoms have normal test results. Other people have abnormal test results but no symptoms.