Numbness is typically a sign that a nerve has been pinched or damaged. Other symptoms that may go along with nerve trouble, other than numbness, would include shooting electricity sensations and weakness of the muscles in the hand.
The most common cause of numbness in the part of the hand that you describe (the ring finger) would be
carpal tunnel syndrome, which is a condition in which the median nerve, which runs down the center of the wrist, becomes pinched or inflamed. This causes numbness and other symptoms primarily in the fingers on the thumb-side half of the hand.
Carpal tunnel syndrome is essentially a repetitive use injury, and as such it is most common in those who work with their hands a lot. For example, people who type at a keyboard all day will frequently suffer from carpal tunnel syndrome.
You should see your
primary care doctor about this issue. The initial treatments for confirmed carpal tunnel syndrome include rest, splinting of the wrist, and anti inflammatory medications. Your doctor can help you decide whether or not any of these treatment are necessary in your case, and they can follow up with you afterwards to make sure that the symptoms are improving.