The causes of carpal tunnel syndrome fall into two basic categories. One category is simply unknown cause, people who are prone to develop carpal tunnel syndrome. The medical word we use for that is an idiopathic condition. That means it happens, but we can’t identify a specific cause. The other group of people who develop carpal tunnel syndrome, develop the condition as a result of some underlying medical problem or a physical problem. The medical conditions that are most often associated with carpal tunnel syndrome, are pregnancy, rheumatoid arthritis, diabetes, and uncontrolled hypothyroidism. Trauma to the hand and wrist or vigorous over use of the hand and wrist can also precipitate carpal tunnel symptoms. So taking those two groups combined, the unknown cause and the direct result from underlying conditions, that gives us the overall 5% distribution of carpal tunnel syndrome in the population.