Now that you have seen the anatomy of a normal wrist, let's look at what happens during carpal tunnel syndrome.
The carpal tunnel and the space allowed for the median nerve and tendons cannot get bigger because the bones and ligaments that form the tunnel will not stretch. Therefore, anything that adds to this space will compress the tendons and median nerve. Most often the synovium around each tendon becomes inflamed and swells. This causes compression of the median nerve, and results in symptoms.
As the median nerve is squeezed, less blood and nutrients flow to it. Without these essential nutrients, it becomes damaged and is unable to function normally. This causes pain, numbness and weakness in the fingers and thumb that is often most noticeable at night. The longer the nerve is squeezed, the more the nerve is damaged. This damage can cause scar formation within the nerve, which is irreversible.
Furthermore, if the nerve is compressed for a long period of time, the muscles in the hand that receive signals from the nerve shrink in size due to the lack of stimulation from the nerve. The longer the nerve is compressed, the more severe the muscle loss.
The sooner the pressure on the median nerve is relieved, the better the chance for recovery.