Although it might seem that carpal tunnel syndrome is a condition born from long hours spent working on a computer keyboard, carpal tunnel syndrome actually has numerous causes.
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. Pressure placed on 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. Other common carpal tunnel syndrome symptoms include:
When to see a doctor
If you have persistent signs and symptoms that might be due to carpal tunnel syndrome that interfere with your normal activities — including sleep — see your doctor. If you leave the condition untreated, nerve and muscle damage can occur.
The cause of carpal tunnel syndrome is pressure on the median nerve. The median nerve is a mixed nerve, meaning it has a sensory function and also provides nerve signals to move your muscles (motor function). The median nerve provides sensation to your thumb, index finger, middle finger and the middle-finger side of the ring finger.
Pressure on the nerve can stem from anything that reduces the space for it in the carpal tunnel. Possible causes include:
Some research suggests that carpal tunnel syndrome can result from overuse or strain in certain job tasks that require a combination of repetitive, forceful, and awkward or stressed motions of your hands and wrists. Examples of these include using power tools — such as chippers, grinders, chain saws or jackhammers — and heavy assembly line work, such as occurs in a meatpacking plant. Although repetitive computer use is commonly assumed to cause carpal tunnel syndrome, the scientific evidence for this association isn't definitive.
Although it's not clear which activities can cause carpal tunnel syndrome, if your work or hobbies are hand-intensive — involving a combination of awkward, repetitive wrist or finger motions, forceful pinching or gripping, and working with vibrating tools — you may be at higher risk of developing the condition.
Other risk factors include:
Your doctor will likely want to review your signs and symptoms to find out where they're located. One diagnostic key is that the median nerve doesn't provide sensation to the little finger, so symptoms in that finger may indicate a different problem. 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.
Your doctor will also 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 either bending the wrist, tapping on the nerve or simply pressing on the nerve, can bring on the symptoms in many people.
If you have signs and symptoms of carpal tunnel syndrome, your doctor may recommend the following diagnostic tests:
These tests are also useful in checking for other conditions that might mimic carpal tunnel syndrome, such as a pinched nerve in your neck. Imaging tests, such as MRI or X-ray, generally aren't used to diagnose carpal tunnel syndrome.
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.
Some people with mild symptoms of carpal tunnel syndrome can ease their discomfort by taking more-frequent breaks to rest their hands and applying cold packs to reduce occasional swelling. If these techniques don't offer relief, carpal tunnel syndrome treatment options include wrist splinting, medications and surgery.
Nonsurgical therapy
Most people with carpal tunnel syndrome experience effective treatment with nonsurgical methods, including:
If carpal tunnel syndrome results from an inflammatory arthritis, such as rheumatoid arthritis, then treating the underlying condition generally also reduces the carpal tunnel syndrome symptoms.
Surgery
Generally, nonsurgical treatments may be more effective if you have only mild nerve impairment. When the pain or numbness of carpal tunnel syndrome persists more than six months, surgery may be the best option.
Your surgeon may use one of a few accepted techniques. But in all accepted surgical procedures, your doctor cuts the ligament pressing on your nerve. At times, surgery can be done using an endoscope, a telescope-like device with a tiny camera attached to it that allows your doctor to see inside your carpal tunnel and perform the surgery through small incisions in your hand or wrist. In other cases, surgery involves making a larger incision in the palm of your hand over the carpal tunnel and releasing the nerve.
Surgery usually results in marked improvement, but you may experience some residual numbness, pain, stiffness or weakness. Surveys of people who have undergone carpal tunnel release indicate that about 70 percent are completely or very satisfied with the outcome of their surgery. Some variables that are associated with lower levels of satisfaction include drinking more than two alcoholic drinks a day, smoking, lower mental and physical health status before surgery, and exposure to repetitive, forceful activity.
Soreness or weakness may take from several weeks to as long as a few months to resolve. If surgery appears to be the best alternative for relieving your symptoms or preventing further muscle degeneration, be sure to talk with your surgeon about the procedure that will work best for you and with your plans to return to your previous activity levels, both at work and at home.
Quick breaks, stretching, aspirin or other over-the-counter NSAIDs — such as ibuprofen (Advil, Motrin, others) and naproxen (Aleve, others) — may relieve your symptoms temporarily.
You might also want to try wearing a wrist splint at night and avoid sleeping on your hands to help ease the pain or numbness in your wrists and hands. The splint should be snug but not tight. If pain, numbness or weakness recurs and persists, see your doctor.
Yoga and other relaxation techniques may help with chronic pain that occurs with some muscle and joint conditions. Yoga postures designed for strengthening, stretching and balancing each joint in the upper body, as well as the upper body itself, may help reduce the pain and improve the grip strength of people with carpal tunnel syndrome.
Although some people use acupuncture or chiropractic therapy to treat carpal tunnel syndrome, these techniques haven't been proved in clinical trials. Supplements of vitamin B-6 may be helpful for relieving the symptoms of carpal tunnel syndrome. Ultrasound treatments also may be used, but have had variable results in studies. Electrical stimulation, magnet therapy and laser treatments haven't provided the same benefits in controlled trials.
You may have to experiment to find a treatment that works for you. Still, always check with your doctor before trying any complementary or alternative treatment.
If you experience chronic pain or can't use your hands as before, you may become depressed or experience low self-esteem. In addition, if your hand symptoms are caused or worsened by your current profession or leisure activities, you may face the tough decision of switching careers or giving up hobbies. You may also feel that you aren't actively contributing to your family if you can't drive a car or perform ordinary household tasks.
Support groups for people with carpal tunnel syndrome can help you find out more information about your condition plus offer advice and solace from those who've lived with carpal tunnel syndrome. Stress management and relaxation techniques also may help you deal with the psychological and emotional issues that may accompany carpal tunnel syndrome.
There are no proven strategies to prevent carpal tunnel syndrome, but to protect your hands from a variety of ailments, take the following precautions: