You ask appropriate questions about whether it can spread, or whether this is from nerve damage. There are three main nerves that provide sensation to the hand; the median nerve, ulnar nerve, and the radial nerve. The radial nerve provides sensation to half of the ventral (palm) side of the thumb, and the dorsal (back of the hand) thumb, as well as the dorsal aspect of the proximal half of the first three fingers and the half of the back of the hand on the thumb side. The other half of the back of the hand gets its sensation from the ulnar nerve, with the exception of the dorsal tips of the first three digits. The palm is innervated by the median nerve, except for the ventral 5th digit ("pinky") which is innervated by the ulnar nerve. There is a medical condition called carpal tunnel syndrome in which the patient can have deficits or neuropraxia (abnormal nerve function) due to compression of the median nerve as it passes through the carpal tunnel in the wrist. This gives an abnormal (or numb sensation) in the area supplied by the median nerve (palm, back of the tips of the index, middle, and ring fingers). There is something called the transverse carpal ligament that can be too tight, and may need to be surgically cut or loosened. I would recommend that you start out by seeing your primary care physician
and they can refer you to the appropriate specialist if needed (perhaps an orthopedic surgeon
, or hand specialist) as there are a number of other medical conditions that can give numbness
. I hope that this helps.