Carpal tunnel syndrome is caused by pressure on a nerve (the median nerve) in the wrist. The symptoms include tingling, numbness, weakness, or pain felt in the fingers, thumb, hand, and sometimes into the forearm.

Conditions that may contribute to the development of carpal tunnel syndrome include pregnancy, hypothyroidism, diabetes, arthritis, and obesity. Improper or prolonged use of the hands or wrist can also put pressure on the median nerve by causing swelling or thickening of tissues close to or within the carpal tunnel. Prior wrist injuries (especially fractures) make a person more likely to develop carpal tunnel syndrome.

Both work and recreational activities can cause carpal tunnel syndrome if done over a long period of time. Some of these activities include:

• Use of tools, especially those that vibrate (such as sanders).
• Assembly work, such as working on a food-processing line.
• Typing, using a computer mouse, or bar-code scanning.
• Prolonged knitting or needlework.
• Prolonged twisting of the wrist.

Carpal tunnel syndrome can often be treated by avoiding activities that irritate the wrist, applying ice, wearing a night splint, and taking anti-inflammatory medicines. Avoiding caffeine, alcohol, and tobacco may help. Strengthening the arms and shoulders and increasing vitamin B6 intake may also help. In some cases, surgery may help.