Carpus is a word derived from the Greek word karpos, which means "wrist." The wrist is surrounded by a band of fibrous tissue that normally functions as a support for the joint. The tight space between this fibrous band and the wrist bone is called the carpal tunnel. The median nerve passes through the carpal tunnel to receive sensations from the thumb, index, and middle fingers of the hand.
Carpal tunnel syndrome is a hand and arm condition that causes numbness, tingling and other symptoms. Carpal tunnel syndrome is caused by a pinched nerve in your wrist. Any condition that causes swelling or a change in position of the tissue within the carpal tunnel can squeeze and irritate the median nerve. Irritation of the median nerve in this manner causes tingling and numbness of the thumb, index, and the middle fingers a condition known as "carpal tunnel syndrome."
A number of factors can contribute to carpal tunnel syndrome, including the anatomy of your wrist, certain underlying health problems and possibly patterns of hand use.
Bound by bones and ligaments, the carpal tunnel is a narrow passageway located on the palm side of your wrist. This tunnel protects a main nerve to your hand and the nine tendons that bend your fingers.
Compression of the nerve produces the numbness, tingling and, eventually, hand weakness that characterize carpal tunnel syndrome. Fortunately, for most people who develop carpal tunnel syndrome, proper treatment usually can relieve the tingling and numbness and restore wrist and hand function.
Carpal tunnel syndrome usually starts gradually with numbness or tingling in your thumb, index and middle fingers that comes and goes. This may be associated with discomfort in your wrist and hand. Common carpal tunnel syndrome symptoms include:
Carpal tunnel syndrome occurs as a result of compression of the median nerve.
The median nerve runs from your forearm through a passageway in your wrist (carpal tunnel) to your hand. It provides sensation to the palm side of your thumb and fingers, with the exception of your little finger. It also provides nerve signals to move the muscles around the base of your thumb (motor function).
In general, anything that crowds, irritates or compresses the median nerve in the carpal tunnel space can lead to carpal tunnel syndrome. For example, a wrist fracture can narrow the carpal tunnel and irritate the nerve, as can the swelling and inflammation resulting from rheumatoid arthritis.
In many cases, no single cause can be identified. It may be that a combination of risk factors contributes to the development of the condition.
Carpal tunnel syndrome should be treated as early as possible after you begin to experience symptoms. Some people with mild symptoms of carpal tunnel syndrome can ease their discomfort by taking more frequent breaks to rest their hands, avoiding activities that worsen symptoms and applying cold packs to reduce occasional swelling.
If these techniques don't offer relief within a few weeks, additional treatment options include wrist splinting, medications and surgery. Splinting and other conservative treatments are more likely to help you if you've had only mild to moderate symptoms for less than 10 months.