Carpal tunnel syndrome is a common condition affecting the wrist and hand. It is caused by pressure on the median nerve in the wrist area, and is characterized by pain, numbness or weakness.

The carpal tunnel is a narrow passageway in the wrist that is formed by a ligament and the small wrist bones. The median nerve runs from the forearm to the hand through the carpal tunnel. Several factors can lead to increased pressure on the median nerve, including:

  • Injury to the wrist that causes swelling (e.g. sprain or fracture)
  • Repetitive activities using the hand or wrist
  • Obesity
  • Overactivity of the pituitary gland
  • Hypothyroidism
  • Rheumatoid arthritis
  • Diabetes and other metabolic disorders that affect the nerves
  • Mechanical problems in the wrist joint
  • Work stress
  • Use of vibrating hand tools
  • Fluid retention during pregnancy or menopause
  • A cyst or tumor in the carpal tunnel

Symptoms typically start off mild and get worse over time. They often first appear in the night and eventually become a problem during the day, too. Symptoms include:

  • Pain, weakness, or numbness in the hand and wrist that may radiate up the arm
  • Burning, tingling, or itching numbness in the palm of the hand and the fingers
  • Decrease in grip strength that results in difficulty making a fist, grasping small objects, or performing other manual tasks

Carpal tunnel syndrome is three times more common in women than in men, three times more common among assembly line workers than data-entry personnel, and overall more common in people with diabetes or other meta­bolic disorders that affect the nerves.