Carpal tunnel syndrome is numbness, tingling, weakness, and other problems in your hand because of pressure on the median nerve in your wrist.
Causes
Carpal tunnel syndrome occurs when a combination of health conditions and activities puts pressure on the median nerve as it passes through the carpal tunnel in your wrist. This pressure leads to symptoms. Anything that decreases the amount of space in the carpal tunnel, increases the amount of tissue in the tunnel, or increases the sensitivity of the median nerve can lead to carpal tunnel syndrome.
Things that help cause carpal tunnel syndrome include:
- Conditions or illnesses that can cause or contribute to arm pain or swelling in the joints and soft tissues in the arm, or to reduced blood flow to the hands. These include obesity, rheumatoid arthritis, gout, diabetes, lupus, and hypothyroidism.
- Repeated hand and wrist movements. They can cause the membranes surrounding the tendons to swell (tenosynovitis).
- Broken wrist bones, dislocated bones, new bone growth from healing bones, or bone spurs. These can take up space in the carpal tunnel and put more pressure on the median nerve.
Carpal tunnel syndrome is a common work-related condition. It can be caused by work that requires:
- Forceful or repetitive hand movements.
- Hand-arm vibration.
- Working for long periods in the same or awkward positions.
Carpal tunnel syndrome is even more likely if you have these work-related issues along with other health conditions.
Symptoms
Mild carpal tunnel symptoms most often affect the hand and sometimes the forearm, but they can spread up to the shoulder. Symptoms include:
- Numbness or pain in your hand, forearm, or wrist that awakens you at night. (Shaking or moving your fingers may ease this numbness and pain.)
- Occasional tingling, numbness, “pins-and-needles” sensation, or pain. The feeling is similar to your hand “falling asleep.”
- Numbness or pain that gets worse while you are using your hand or wrist. You are most likely to feel it when you grip an object with your hand or bend (flex) your wrist.
- Occasional aching pain in your forearm between your elbow and wrist.
- Stiffness in your fingers when you get up in the morning.
With moderate or severe carpal tunnel symptoms, you may have numbness or reduced strength and grip in your fingers, thumb, or hand. It may be hard to:
- Do simple hand movements, such as brushing your hair or holding a fork. You may accidentally drop objects.
- Pinch an object between your thumb and first finger. (This is called loss of pinch strength.)
- Use your thumb while doing simple tasks such as opening a jar or using a screwdriver. With long-term carpal tunnel syndrome, the thumb muscles can get smaller and weaker (atrophy).
- Symptoms most often occur in parts of the hand camera.gif supplied by the median nerve: the thumb, the index finger, the middle finger, and half of the ring finger. The median nerve doesn’t affect your little finger. So if your little finger is affected, you may not have carpal tunnel syndrome.
Diagnosis
Medical history. The doctor will ask about any medical problems or illnesses, prior injuries, current symptoms, or daily activities that may be causing your symptoms.
Hand diagram. You may be asked to help fill in a diagram of your hand to show where you have numbness, tingling, or pain.
Physical exam, including comparing the strength of both hands.
>More testing
If your symptoms are severe, if nonsurgical treatment has not improved symptoms, or if your symptoms aren’t clearly caused by carpal tunnel syndrome, your doctor may recommend:
- Nerve testing, which checks the median nerve.
- X-rays. These can check for bone problems caused by past injury, arthritis, recently broken or dislocated bones, or tumors. X-rays aren’t used to diagnose carpal tunnel syndrome. But they can be helpful for finding signs of arthritis or an old or new wrist or neck injury that may be adding to your symptoms.
- Ultrasound, to look at the size of the median nerve. It is inexpensive, comfortable, and quick. But its use for carpal tunnel syndrome diagnosis is still unproven and fairly uncommon.
- MRI. This imaging test can find swelling of the median nerve, narrowing of the carpal tunnel, or problems with circulation of blood through the carpal tunnel.
- Blood tests. These are sometimes done to check for a thyroid problem, rheumatoid arthritis, or another medical problem.
Treatment
The goal of treatment for carpal tunnel syndrome is to allow you to return to your normal function and activities and to prevent nerve damage and loss of muscle strength in your fingers and hand.
Treatment options include:
- Home treatment, such as changing or avoiding activities that may be causing symptoms and wearing a wrist splint.
- Physical therapy. This includes ultrasound, stretching, and range-of-motion exercises. In some clinics, these therapies may be done by an occupational therapist.
- Medicines, such as nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and reduce inflammation. In some cases, oral corticosteroids or corticosteroid injections into the carpal tunnel may be considered.
- Surgery. Surgery is sometimes recommended when other treatment hasn’t helped, if you’ve had carpal tunnel syndrome for a long time, or if there is nerve damage or the risk of nerve damage.