Carpal tunnel syndrome is a progressively painful hand and arm condition caused by a pinched nerve in your wrist. 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 — about as big around as your thumb — located on the palm side of your wrist. This tunnel protects a main nerve to your hand and nine tendons that bend your fingers. Compression of the nerve produces the numbness, pain and, eventually, hand weakness that characterize carpal tunnel syndrome.
Fortunately, for most people who develop carpal tunnel syndrome, proper treatment usually can relieve the pain and numbness and restore normal use of their wrists and hands. Carpal tunnel syndrome typically starts gradually with a vague aching in your wrist that can extend to your hand or forearm. Common carpal tunnel syndrome symptoms include:
• Tingling or numbness in your fingers or hand, especially your thumb and index, middle or ring fingers, but not your little finger. This sensation often occurs while holding a steering wheel, phone or newspaper or upon awakening. Many people "shake out" their hands to try to relieve their symptoms. As the disorder progresses, the numb feeling may become constant.
• Pain radiating or extending from your wrist up your arm to your shoulder or down into your palm or fingers, especially after forceful or repetitive use. This usually occurs on the palm side of your forearm.
* A sense of weakness in your hands and a tendency to drop objects.
Your doctor may conduct one or more of the following tests to determine whether you have carpal tunnel syndrome:
• History of symptoms. The pattern of your signs and symptoms may offer clues to their cause. For example, since the median nerve doesn't provide sensation to your little finger, symptoms in that finger may indicate a problem other than carpal tunnel syndrome. Another clue is the timing of the symptoms. Typical times when you might experience symptoms due to carpal tunnel syndrome include while holding a phone or a newspaper, gripping a steering wheel, or waking up during the night.
• Physical exam. Your doctor will want to test the feeling in your fingers and the strength of the muscles in your hand, because these can be affected by carpal tunnel syndrome. Pressure on the median nerve at the wrist, produced by bending the wrist, tapping on the nerve or simply pressing on the nerve, can bring on the symptoms in many people.
• X-ray. Some doctors may recommend an X-ray of the affected wrist to exclude other causes of wrist pain, such as arthritis or a fracture.
• Electromyogram. Electromyography measures the tiny electrical discharges produced in muscles. A thin-needle electrode is inserted into the muscles your doctor wants to study. An instrument records the electrical activity in your muscle at rest and as you contract the muscle. This test can help determine if muscle damage has occurred.
• Nerve conduction study. In a variation of electromyography, two electrodes are taped to your skin. A small shock is passed through the median nerve to see if electrical impulses are slowed in the carpal tunnel.
The electromyogram and nerve conduction study tests are also useful in checking for other conditions that might mimic carpal tunnel syndrome, such as a pinched nerve in your neck.
Your doctor may recommend that you see a rheumatologist, neurologist, hand surgeon or neurosurgeon if your signs or symptoms indicate other medical disorders or a need for specialized treatment.
If you have persistent signs and symptoms suggestive of carpal tunnel syndrome, especially if they interfere with your normal activities and sleep patterns, see your doctor. If you leave the condition untreated, nerve and muscle damage can occur.