Any pathological process that compromises space for the median nerve may cause carpal tunnel syndrome.
- there appears to be an anatomical predisposition with females affected three times more often than males.
 - 60% of patients are aged between 40 and 60 years.
 
CTS is mostly an idiopathic syndrome. Certain risk factors have been described associated with this syndrome:
- environmental risk factors – hand in extremes of wrist flexion or extension for prolonged period of time, repetitive use of the flexor muscles, and exposure to vibration
 - medical risk factors 
- extrinsic risk factors – there is an increase in the volume within the tunnel e.g. - pregnancy, menopause, obesity, renal failure, hypothyroidism, the use of oral contraceptives and congestive heart failure
 - intrinsic risk factor - increased occupied volume inside the tunnel e,g, - tumours and tumour-like lesions
 - extrinsic factors that alter the contour of the tunnel – e.g. - after fractures of the distal radius, directly or via posttraumatic arthritis
 - neuropathic factors – e.g. - diabetes, alcoholism, vitamin toxicity or deficiency, and exposure to toxins (1)
 
 
The causes of CTS can also be classified into:
- endocrine causes
 - infiltrative causes
 - others
 
Pregnancy and rheumatoid arthritis are the most likely causes of carpal tunnel syndrome in young patients
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