Carpal Tunnel Syndrome
What is carpal tunnel syndrome?
The carpal tunnel is a narrow passageway inside the wrist on the palm side (carpal means wrist). The main nerve to the hand (median nerve) and nine tendons that bend the fingers are within the tunnel. Carpal tunnel syndrome occurs when the median nerve is compressed at the wrist by inflammation of the nerve, tendons, or ligaments that cross the tunnel. Information about Carpal Tunnel and other musculo-skeletal injuries can be found on the Environmental Health ergonomics page.
What causes carpel tunnel syndrome?
Pressure on the median nerve can stem from anything that reduces the space in the carpal tunnel. The exact cause cannot usually be identified, but common factors that contribute to the development of carpal tunnel syndrome are:
- Certain medical conditions that impact the nerves, such as rheumatoid arthritis or metabolic conditions (like diabetes, pregnancy, weight gain, and thyroid disease).
- Repetitive flexing and extending of the tendons in the hands and wrists, particularly when done for prolonged periods without rest.
- The physical characteristics of the carpal tunnel, such as being narrower than average.
What are the symptoms of carpal tunnel syndrome?
Each person experiences carpal syndrome differently; thus, some or all of the following symptoms might be present:
- Numbness or tingling in the hand and fingers (usually any or all fingers but the little finger)
- Shooting pain up the forearm on the palm side
- Weakness in the hands and difficulty holding things
- Constant loss of feeling in some fingers
How is carpal tunnel syndrome diagnosed?
Your healthcare provider will take a careful history of your symptoms. He or she might perform two simple tests during your visit: the Tinel test and the Phalen test. For the Tinel test, your provider will tap the palm side of your wrist to see if tingling sensations in your fingers occur. The Phalen test involves pressing your hands back to back (palm sides facing out) for 30-60 seconds to see if your symptoms are reproduced. Tests to determine loss of strength and/or sensation may be done in the initial visit.
If carpal tunnel syndrome is suspected because of the presence of weakness or numbness, your healthcare provider may request an electromyography (EMG). An EMG sends electrical impulses through the nerves of the hand and arm to measure how quickly the impulses are conducted. Conduction indicates the extent and location of nerve damage. A referral to a hand specialist or neurologist will be necessary for this test to be done.
How is carpal tunnel syndrome treated?
Initial treatment usually involves resting the affected hand(s) and wrist(s) by avoiding activities that worsen the symptoms and immobilizing the wrist(s) in a splint. Stretching and strengthening exercises are usually recommended, as is use of an over-the-counter pain medication. Corticosteroid injections can be used to reduce swelling and symptoms. In severe cases carpal tunnel release surgery is performed, which involves enlarging the carpal tunnel to relieve pressure. Symptoms can often be reduced or prevented by using a properly set up workstation. Sometimes the design of the workstation needs to be modified.
How can carpal tunnel syndrome be prevented?
While there is no proven way to prevent carpal tunnel syndrome, you can reduce your risk of experiencing discomfort in your hands and wrists by following the tips below:
- Keep your wrists straight while you sleep - a splint can help.
- Keep your wrists straight, reduce your force, and relax your grip when doing activities that involve your hands.
- While working, take frequent rest breaks, wear splints to keep wrists straight, and use correct posture and wrist position.
- Ensure that your work station is ergonomically correct. The IUPUI Department of Environmental Health and Safety provides workplace ergonomic resources. See Ergonomics at IU. Workstation evaluations may be requested by clinic providers or supervisors.
- Use both hands to lift heavy charts, books or other objects.
- Use a wrist rest on your computer keyboard.
- Strengthen your wrists and forearms.