There are several common causes of hand tingling. Carpal tunnel syndrome tends to be one of the most common causes of hand tingling. One of the nerves that supply the hand is called the Median nerve. This nerve travels across the wrist to supply the fingers. With repetitive bending and straightening of the wrist this nerve gets injured. This tends to occur in people that use the computer frequently, use the cash register, or are involved in activities that involve repetitive motion at the wrist.
Another nerve that supplies the hand is called the Ulnar nerve. This nerve passes behind the elbow and could get injured at that point. One of the common causes of injury is from leaning on the elbow which causes pressure on the nerve. Other common causes include pressure from surrounding tissue, arthritis, and injury to the elbow.
Since the nerves that supply the hands originate in the spine, injury to the nerves at this level could cause numbness, tingling, and weakness in the hands. Generally patients often have shooting pain down the arm with this kind of a problem. There could be multiple causes like disk disease, tumors, and arthritis.
Systemic disease like diabetes, kidney failure, infections, and others could cause injury to the nerves so that patients could develop weakness and numbness in their hands. These patients often also have numbness and tingling in their feet first. These patients most often have Neuropathy.