The carpal tunnel is a narrow, fibrous passage in the wrist that protects the median nerve, which runs down the length of arm and through the wrist into the hand. It controls some hand movement, and sensation in the thumb, index and middle fingers, and half of the ring finger. Irritation or compression of the median nerve within the carpal tunnel can cause tingling and numbness in the fingers, a condition known as carpal tunnel syndrome (CTS).
Symptoms of Carpal Tunnel Syndrome
CTS develops gradually, usually beginning as an ache in the wrist that extends up the forearm or down into the hand. As CTS worsens, there may be tingling or numbness in the fingers, or pain radiating through the entire arm. Some people also experience weakness in the hand and arm, and have difficulty grasping small objects. These symptoms are usually most severe when a person first wakes up.
Although most people associate carpal tunnel syndrome with pain and tingling in the fingers, it should be noted that the "pinky" finger is not affected. Anyone experiencing symptoms in the pinky may be suffering from another condition.
Risk Factors for Carpal Tunnel Syndrome
In most cases, the causes of CTS remain unknown. In some instances, CTS is the result of genetic predisposition, with some people having atypically small carpal tunnels, making the median nerve more susceptible to irritation. Whether CTS is caused by repetitive motions such as using a computer mouse has not been proven conclusively. Risk factors for CTS include the following:
- Inflammatory conditions (such as arthritis)
- Fluid retention
- Thyroid disorders
- Kidney failure
- Use of oral contraceptives
Symptoms can be triggered by any pressure placed on the median nerve.
Diagnosis of Carpal Tunnel Syndrome
Carpal tunnel is usually diagnosed through a complete medical history and physical examination. Diagnostic tests such as an electromyogram, which records the electrical activity of nerves and muscles, may be performed.
Treatment of Carpal Tunnel Syndrome
Often, CTS can be effectively treated by avoiding or modifying the activity that is causing symptoms. Additional treatments may include the following:
- Resting the hands
- Applying cold packs
- Taking anti-inflammatory medication
- Getting corticosteroid injections
- Wearing splints
- Getting physical therapy
More severe cases of CTS, such as those that interfere with normal daily activities or are caused by nerve damage, may be treated surgically by cutting the ligament that is pressing on the median nerve. Either endoscopy or open surgery can be used. Postsurgery, activities known to have caused CTS should be stopped, or performed differently.