What does it mean if your entire hand randomly goes numb throughout the day?

Hand numbness: This could be a manifestation of a nerve problem. The hand is enervated by the median, radial and ulnar nerves. The median nerve enervates the thumb and little finger and the other nerves the rest. It is unusual for the whole hand to go numb unless there is a problem higher up in the brachial plexus or spine. You need a neurological evaluation by a neurologist and X-rays of your spine.