The old expression “the straw that broke the camel’s back” is quite appropriate in human diseases. Carpal tunnel syndrome is a disease of a nerve usually caused by compression, a pinched nerve. if you will. The nerves to the hand originate from the neck, move down the shoulder and arm, and then pass through a narrow tunnel in the wrist formed by eight carpal bones. Most of the time, when a nerve is slightly pinched, we will not notice it at all. Only when the pressure gets to be substantial will the symptoms of pain and tingling become more pronounced.
Many people will have slight neck problems that affect the openings between the vertebrae in the neck that the nerves must pass. This is called subluxation, when vertebrae move out of their normal position, and can result from neck traumas such as whiplash or head impacts.
Many will have slight compression of the nerves in the neck but not notice it until the nerve is further pinched at the wrist. Others will have compression at both sites and still not notice anything unless they use their wrist repetitively. It is known that repetitive movements of the wrist are a risk factor (a straw) for producing carpal tunnel syndrome.
When the musculoskeletal system is taxed through trauma, sport and even pregnancy (Baumann, et. al. Neurol Neurophysiol Neurosci 2007;Aug 2:3), the nerves can then show symptoms. One study looked at women in early and late pregnancy. Eleven percent of pregnant women showed nerve conduction signs of carpal tunnel syndrome but did not yet have symptoms. As their pregnancies advanced, the stresses on the spine increased and many of these patients then started showing symptoms at the end of the pregnancy.