What is Carpal Tunnel Syndrome?
At the base of the palm is a tight canal or “tunnel” through which tendons and nerves must pass on their way from the forearm to the hand and fingers. The nerve that passes through this narrow tunnel to reach the hand is called the Median Nerve. This narrow passage between the forearm and hand is what we call “The Carpal Tunnel”.
The Carpal Tunnel is normally quite snug and there is just barely enough room in it for the tendons and nerves that have to pass through it. If anything takes up extra room in the canal, things become too tight and the nerve in the canal becomes constricted or “pinched”. This pinching of the nerve causes numbness and tingling in the area of the hand that the nerve travels to. The condition that results when the Median Nerve is being pinched in The Carpal Tunnel is commonly referred to as “Carpal Tunnel Syndrome” or “CTS”.
What Can Cause Carpal Tunnel Syndrome?
Like many skeletomuscular disorders, CTS has a variety of causes. It is most often the result of a combination of factors. Among these are:
Genetic predisposition. Certain people are more likely than others to get CTS. The amount of natural lubrication of the flexor tendons varies from person to person. The less lubrication, the more likely is CTS. One study has related the cross-sectional shape of the wrist, and the associated geometry of the carpal tunnel, to CTS. Certain tunnel geometries are more susceptible to tendon irritation.
Health and lifestyle. People with diabetes, gout, and rheumatoid arthritis are more prone than others to develop CTS, as are those experiencing the hormonal changes related to pregnancy, menopause, and the use of birth control pills. Job stress has also been linked to an increased likelihood of CTS. And CTS seems to be more frequent among alcoholics.
Repetitive motion. The most common cause of CTS that's been attributed to the workplace is repetitive motion. When you flex your hand or fingers the flexor tendons rub against the walls of the carpal tunnel. If you allow your hand time to recover, this rubbing is not likely to lead to irritation. The amount of recovery time you need varies from fractions of a second to minutes, depending on many circumstances, including the genetic and health factors mentioned above, as well as the intensity of the flexing, the weight of any objects in your hand, and the extent to which you bend your wrist during flexing.
- Trauma. A blow to the wrist or forearm can make the tendons swell and cause or encourage the onset of CTS.
The most common cause of Carpal Tunnel Syndrome is inflammation of the tendons in the tunnel which can normally be attributed to repetitive use of the hand and/or wrist.
Repetitive Strain Injuries (RSIs) can happen to anyone whose work calls for long periods of steady hand movement, from musicians & dental hygienists to meat cutters & cashiers. RSIs tend to come with work that demands repeated grasping, turning and twisting; they are especially likely if the work requires repeated twisting or involves repetitive vibration, as in hammering nails or operating a power tool. Stressful hand, arm and neck positions — whether from working at a desk, long-distance driving or waiting on tables — only aggravate the potential for damage.
A number of sports can bring on repetitive stress injuries: Rowing, golf, tennis, downhill skiing, archery, competitive shooting and rock climbing are just a sampling of activities that stress the hand and wrist joints. Injuries and ailments that cause swelling or compression of soft tissue on nerves, such as sprains, leukemia, and rheumatoid arthritis, can lead to stress injuries. Diabetes, thyroid problems, and other systemic disorders are also associated with discomfort from stressed nerves, as is the fluid accumulation that sometimes accompanies pregnancy. Some authorities believe that a pyridoxine (vitamin B6) deficiency can also induce the symptoms. Fluid retention, a major contributor to CTS & RSI symptoms naturally occur with the usage of contraceptive pills. Post Menstrual Syndrome (PMS) also causes fluid retention as do many other medical conditions, all of which can result in Carpal Tunnel Syndrome symptoms.
Carpal Tunnel Syndrome Symptoms
- A tingling or numb feeling in the hand and/or fingers;
- Shooting pains in the wrist or forearm, and sometimes extending to the shoulder, neck and chest, or foot;
- Difficulty clenching the fist or grasping small objects;
- For many unfortunate sufferers, CTS has a pattern of flaring up through the night thereby making sleep difficult. CTS symptoms can also be expected to arise frequently while performing the activity that is the cause of the condition in the first place.