Most commonly the cause of carpal tunnel syndrome is unknown. Known causes and contributory factors include:

  • repetitive movements at the wrist
  • diabetes
  • fluid retention e.g. during pregnancy
  • underactive thyroid
  • rheumatoid arthritis
  • gout – a type of arthritis where crystals form inside and around joints
  • lipomas – soft, fatty lumps that grow under your skin
  • wrist fractures or dislocations