carpal tunnel syndrome

Carpal tunnel syndrome is a condition in which the median (pronounced mee-dee-an) nerve becomes compressed.
The median nerve is the nerve that travels down the arm into the hand. With carpal tunnel syndrome the nerve is squeezed as it passes through the narrow path (or tunnel) at the wrist.

The pressure on the wrist can cause the fingers and thumb to feel tingly and numb. They may feel paralysed, or unable to move.
The median nerve is a large nerve that travels down the centre of the forearm to the skin of the thumb, the index finger, the long middle finger and half of the third, or ring, finger. It also supplies sensation to the muscles of the base of the thumb.

To enter the hand the median nerve must pass through the narrow opening at the wrist joint. On one side of the wrist joint are bones, and on the other is a strong ligament that runs across the wrist. The ligament and the bones form a firm channel that has little ability to expand. Therefore, if this ‘tunnel’ becomes swollen or narrowed any resulting pressure is applied within. Several tendons also pass through this tunnel but it is the median nerve, being the most sensitive nerve in the area, that is most prone to damage from this type of pressure.

If any nerve in the body is bumped or has sustained pressure applied to it, this can cause sensory changes such as tingling or numbness. For example, bumping the 'funny bone' at the elbow can cause tingling or numbness in the fingers.

When pressure is applied to a nerve for a long period this can cause loss of 'motor power' that the nerve supplies to the muscle. For example, if a person sits in an uncomfortable position for a long period of time this can put pressure on the nerves in the legs, causing them to ‘go to sleep’ and feel temporarily paralysed. This same phenomenon occurs with carpal tunnel syndrome, except that with carpal tunnel syndrome the pressure is more constant and ongoing and the resulting symptoms more sustained