What is Carpal Tunnel Syndrome?
- Carpal tunnel syndrome is an irritation of the median nerve in the wrist that leads to numbness, tingling, pain, and weakness in the hand. The median nerve travels down the forearm and enters the hand after passing through the wrist tunnel (carpal tunnel) that is located in the central part of the wrist.
- The syndrome typically affects the thumb, index, and middle fingers and is often particularly troublesome at night.
- Carpal tunnel syndrome affects a low percent of the population and is most common in middle-aged women.
- Any condition that causes increased direct pressure on the median nerve in the wrist can lead to carpal tunnel syndrome. Many people with carpal tunnel syndrome have no identifiable cause.
- Carpal tunnel syndrome is diagnosed based on the complaints of the individual combined with physical tests and often electrical tests. No single test is definitive for diagnosis of carpal tunnel syndrome. Rather, the person's complaints and test findings together lead to its diagnosis.
Carpal Tunnel Syndrome Causes
The following are risk factors associated with the development of carpal tunnel syndrome:
Carpal tunnel syndrome is rare in children.
The relationship between work and carpal tunnel syndrome is unclear. Positions of extreme wrist flexion and extension are known to increase pressures within the carpal canal and apply pressure on the nerve. This is particularly true with repetitive strain injury to the wrist. Intensity, frequency, and duration of work activity and their relationship to carpal tunnel syndrome are unclear.
Carpal Tunnel Syndrome Symptoms and Signs
The following are symptoms associated with carpal tunnel syndrome. You may still have carpal tunnel syndrome if you have only a few symptoms.
Numbness, pain (usually a burning pain), and tingling in your thumb, index, and middle fingers
Tingling, numbness, or pain, which may move up your arm to your elbow
Difficulty feeling and handling small objects
Symptoms are usually worse at night and are sometimes temporarily relieved by "shaking out" your hands.
When to Seek Medical Care for Carpal Tunnel Syndrome
If your symptoms last a long time and are not relieved with recommended home care, you should see your doctor.
Carpal tunnel syndrome is rarely an emergency. Most cases of carpal tunnel syndrome respond to nonsurgical treatment. The first line of treatment for mild carpal tunnel syndrome is to wear a wrist brace. This has been shown to relieve the symptoms from the carpal tunnel by placing the wrist in an optimal position (30 degrees of extension), reducing the nerve irritation. If carpal tunnel syndrome persists for a long time, permanent nerve injury is possible that will cause numbness as well as weakness and atrophy (shrinkage) of muscles in the hand. Treatment is directed at preservation of hand function.
Carpal Tunnel Syndrome Diagnosis
Expect your doctor to perform several simple carpal tunnel syndrome tests to evaluate the nerve function of your hand. You can also perform a few of these tests at home.
Your doctor will most likely start with a visual and manual inspection of your hand looking for any obvious abnormalities that may help to explain your problem.
Range of motion of the wrist is often evaluated. By placing the palms of the hands together, wrist extension can be evaluated. By placing the backs of the hands together, wrist flexion can be evaluated. People who have had prior wrist injuries or wrist arthritis often have abnormalities in wrist range of motion.
The sensation over your hand will often then be checked to see if your sensation of soft touch, pinprick, or two-point discrimination (the ability to feel two points distinctly using a sharp pin on the fingertips) is abnormal in any areas.
The strength in your hands and fingers can be checked, often using your opposite, or good side, for comparison.
Physical tests to evaluate for carpal tunnel syndrome include the following:
Hold your elbows at shoulder level and place the backs of your hands together with your wrists bent at 90 degrees.
Hold this position for 60 seconds.
This position increases the pressure on the median nerve.
If the test reproduces or worsens your symptoms (pain and tingling in your hands), you may have carpal tunnel syndrome.
Have someone hold your wrist as shown in the picture and tap on the palm side of your wrist.
A positive test produces tingling into the thumb, index, or middle fingers. This is a sign of an irritable nerve where the tapping was done.
If this test gives you tingling in your thumb, index, or middle fingers, you may have carpal tunnel syndrome.
You may also be referred to a specialist (neurologist, rheumatologist, or orthopedic surgeon) for evaluation of your nerve conduction or the presence of possible arthritis leading to carpal tunnel syndrome. Nerve conduction testing measures the speed with which an electrical impulse travels in the median nerve across the wrist. For people with carpal tunnel syndrome, this nerve impulse will travel more slowly across the wrist than normal. For people who have advanced carpal tunnel syndrome, measurements of electrical activity in the hand muscles may reveal signs of muscle deterioration.
What Are the Symptoms of Carpal Tunnel Syndrome?
Carpal tunnel syndrome can cause tingling, numbness, weakness, or pain in the fingers or hand. Some people may have pain in their arm between their hand and their elbow.
Symptoms most often occur in the thumb, index finger, middle finger, and half of the ring finger. If you have problems with your other fingers but your little finger is fine, this may be a sign that you have carpal tunnel syndrome. A different nerve gives feeling to the little finger.
You may first notice symptoms at night. You may be able to get relief by shaking your hand.
Home Remedies for Carpal Tunnel Syndrome
Home care for carpal tunnel syndrome is straightforward and can often provide relief for mild cases of carpal tunnel syndrome.
Wear a wrist splint (can be purchased at most drugstores) to keep the wrist in an optimal position at rest. Splinting is usually tried for a period of four to six weeks. Some people wear their splints at night only and others wear their splints both day and night, depending upon when the symptoms are at their worst. If no relief is found at four to six weeks, the splints are not likely to help.
Carpal Tunnel Syndrome Medications and Treatment
Carpal tunnel syndrome is not primarily an inflammatory process. However, pain is a common complaint, and anti-inflammatory medications are sometimes used to try to treat the pain. Anti-inflammatory medications such as ibuprofen (Advil) may provide some relief but are unlikely to cure carpal tunnel syndrome.
Direct injection of steroid medication by your doctor into the carpal canal has been shown to be an effective treatment for some people with carpal tunnel syndrome. This is a procedure that can be done in the doctor's office with only minimal discomfort.
Carpal Tunnel Syndrome Surgery
When nonsurgical treatment has failed or for more advanced cases, surgical treatment of the carpal tunnel syndrome may be considered. The goal of surgery is to take pressure off the nerve at the wrist. Surgery is typically done at an outpatient center. The surgeon will make a small cut over the palmar side of the wrist and then release the ligament that covers the carpal tunnel. By releasing the ligament, the size of the carpal tunnel increases and pressure is relieved on the nerve in the carpal tunnel.
Overall, surgery is very safe, but some risks do exist, including infection, wound healing difficulty, stiffness, wound pain, and nerve injury. Some people experience immediate relief in their hand once the pressure on the nerve is eliminated with surgery. Other people do not experience immediate relief due to more long-standing and severe pressure on the nerve.
After surgery, a dressing is placed over the surgical wound. The fingers are left free for immediate use. Most people feel comfortable to use their hand for light activities within a day or two after surgery. People can return to light jobs three to four weeks after surgery and heavy work about six weeks after surgery.
Other Carpal Tunnel Therapy
Physical therapy can be particularly useful after carpal tunnel surgery. Therapy can reduce swelling, stiffness, and pain after surgery. Therapy can also help to restore strength after surgery. Not everyone needs therapy after surgery, but for some, it can be very helpful.
Follow-up for Carpal Tunnel
- Wear your wrist splint, and take all medications as directed.
- Keep any return appointments, even if you feel better, so your doctor can monitor your progress and make changes to your treatment plan if necessary.
Carpal Tunnel Syndrome Prevention
Avoiding smoking, maintaining an appropriate weight, and regularly exercising may help prevent the onset of carpal tunnel syndrome.
Modification of workstations, keyboards, and tools has been attempted to try to prevent the development of carpal tunnel syndrome. Whether these ergonomic interventions help is unknown. Appropriate treatment of wrist arthritis, when present, can prevent or treat carpal tunnel syndrome.
Carpal Tunnel Syndrome Prognosis
The prognosis for carpal tunnel syndrome is very good.
Mild cases can respond to nonsurgical care, such as bracing and steroid injection.
Advanced cases can be treated very effectively with surgery.
Carpal Tunnel Syndrome Pictures
The shaded area represents the area usually affected by carpal tunnel syndrome. As you can see, it can and usually does involve half of your ring finger as well as your palm and first two fingers. In some people, a part of the thumb may also be involved. Photograph courtesy of Christopher-Patrick Photography, Winston-Salem, NC. Click to view larger image.
Phalen's sign. Hold your hands back-to-back as shown with your wrist bent at 90 degrees. If you develop pain, numbness, or tingling within 60 seconds, you may have carpal tunnel syndrome. Photograph courtesy of Christopher-Patrick Photography, Winston-Salem, NC.Click to view larger image.
Tinel sign. Have someone hold your hand with your wrist bent slightly back. With the other hand, your assistant should tap on your wrist as shown. If you experience pain, numbness, or tingling while they are tapping, you may have carpal tunnel syndrome. You can also perform this on yourself by tapping on your wrist as shown in the picture. Having someone else bend your wrist back slightly is a little more effective. Photograph courtesy of Christopher-Patrick Photography, Winston-Salem, NC. Click to view larger image.
Reviewed on 11/17/2017
Medically reviewed by Aimee V. HachigianGould, MD; American Board of Orthopaedic Surgery
Fauci, A.S., and C.A. Langford. Harrison's Rheumatology New York: McGraw-Hill Medical Publishing, 2006.