The most helpful test for Carpal Tunnel Syndrome is Phalen’s Maneuver.​

Firmly hold the backs of your hands together with your fingers pointing down, while keeping your arms parallel to the floor. If within a minute, you experience numbness, tingling, pain or a combination, you likely have nerve involvement.

Another test is Tinel’s sign. 

Use your finger to repeatedly tap the volar carpal ligament, the ligament just under the skin in the center of your wrist. If the tapping elicits numbness, tingling or pain, then you may well have carpal tunnel syndrome. Often, chiropractic care can be very helpful in resolving this type of problem.