Carpal tunnel syndrome occurs when the median nerve, which runs from the forearm into the palm of the hand, becomes pressed or squeezed at the wrist. The carpal tunnel—a narrow, rigid passageway of ligament and bones at the base of the hand—houses the median nerve and the tendons that bend the fingers. The median nerve provides feeling to the palm side of the thumb and to the index, middle, and part of the ring fingers. It also controls some small muscles at the base of the thumb.
Sometimes, thickening from the lining of irritated tendons or other swelling narrows the tunnel and compresses the median nerve. The result may be numbness, weakness, or sometimes pain in the hand and wrist. CTS is the most common and widely known of the entrapment neuropathies, in which one of the body’s peripheral nerves is pressed on or squeezed.
Most cases of carpal tunnel syndrome are caused by a combination of factors. Studies show that women and older people are more likely to develop the condition. Other risk factors for carpal tunnel syndrome include:
Heredity. This is likely an important factor. The carpal tunnel may be smaller in some people or there may be anatomic differences that change the amount of space for the nerve—and these traits can run in families.
Repetitive hand use. Repeating the same hand and wrist motions or activities over a prolonged period of time may aggravate the tendons in the wrist, causing swelling that puts pressure on the nerve.
Hand and wrist position. Doing activities that involve extreme flexion or extension of the hand and wrist for a prolonged period of time can increase pressure on the nerve.
Pregnancy. Hormonal changes during pregnancy can cause swelling.
Health conditions. Diabetes, rheumatoid arthritis, and thyroid gland imbalance are conditions that are associated with carpal tunnel syndrome.
Symptoms
Symptoms of carpal tunnel syndrome may include:
Numbness, tingling, burning, and pain—primarily in the thumb and index, middle, and ring fingers
Occasional shock-like sensations that radiate to the thumb and index, middle, and ring fingers
Pain or tingling that may travel up the forearm toward the shoulder
Weakness and clumsiness in the hand—this may make it difficult to perform fine movements such as buttoning your clothes
Dropping things—due to weakness, numbness, or a loss of proprioception
In most cases, the symptoms of carpal tunnel syndrome begin gradually—without a specific injury. Many patients find that their symptoms come and go at first. However, as the condition worsens, symptoms may occur more frequently or may persist for longer periods of time.
Night-time symptoms are very common. Because many people sleep with their wrists bent, symptoms may awaken you from sleep. During the day, symptoms often occur when holding something for a prolonged period of time with the wrist bent forward or backward, such as when using a phone, driving, or reading a book.
Your treatment will depend on your symptoms and how far your condition has progressed. You might need:
Lifestyle changes. If repetitive motion is causing your symptoms, take breaks more often or do a bit less of the activity that’s causing you pain.
Exercises. Stretching or strengthening moves can make you feel better. Nerve gliding exercises can help the nerve move better within your carpal tunnel.
Immobilization. Your doctor may tell you to wear a splint to keep your wrist from moving and to lessen pressure on your nerves. You may wear one at night to help get rid of that numbness or tingling feeling. This can help you sleep better and rest your median nerve.
Medication. Your doctor may give you anti-inflammatory drugs or steroid shots to curb swelling.
Surgery. If none of those treatments works, you might have an operation called carpal tunnel release that increases the size of the tunnel and eases the pressure on your nerve.
Carpal Tunnel Syndrome Prevention
To avoid carpal tunnel syndrome, try to:
Keep your wrists straight.
Use a splint or brace that helps keep your wrist in a neutral position.
Avoid flexing and extending your wrists over and over again.
Keep your hands warm.
Take breaks whenever you can.
Put your hands and wrists in the right position while you work.
For most patients, surgery will improve the symptoms of carpal tunnel syndrome. Recovery, however, may be gradual and complete recovery may take up to a year. If you have significant pain and weakness for more than 2 months, your doctor may refer you to a hand therapist who can help you maximize your recovery.
If you have another condition that causes pain or stiffness in your hand or wrist, such as arthritis or tendonitis, it may slow your overall recovery. In long-standing cases of carpal tunnel syndrome with severe loss of feeling and/or muscle wasting around the base of the thumb, recovery will also be slower. For these patients, a complete recovery may not be possible.
