The reason it starts at night is due to nerve cooling and the fact that nerves do not work as well when they are cold. In addition, if the wrists are held in an extremely bent condition either down or up, the nerve can be compressed or stretched and cause the numbness at night.
Treatment for Carpal Tunnel Syndrome really starts with an EMG Nerve Test. The reason it starts with a nerve test is because the EMG Nerve Test can not only confirm Carpal Tunnel Syndrome, but also helps “grade” the condition. Grading the condition to determine how badly the Median Nerve is damaged is the key to knowing what treatment will be helpful.
Specialized Therapy from a Certified Hand Therapist trained in Occupational Therapy (OT), or very often physical therapy, can resolve the symptoms. Other than the usual treatments provided by the therapist such as nerve glides and education, the use of iontophoresis to place special anti-inflammatories into the area of the nerve can be very helpful. Wrist braces worn primarily at night can also be part of the healing and calming of the nerve irritation.