This symptom makes me think immediately of carpal tunnel syndrome. Carpal tunnel syndrome is an overuse injury
which occurs when the median nerve, which is a nerve that runs down the inside surface of the wrist becomes inflamed. As you probably know, the most common reason for developing carpal tunnel syndrome is repetitive actions which involve bending the wrist, such as typing on a computer keyboard.
The median nerve is involved in sensation to the first three fingers of the hand (thumb, index, and middle fingers) as well as muscles in those areas. Therefore, inflammation of the median nerve will cause numbness, pain, or tingling
in those fingers. It can also cause weakness of the associated muscles, for example, when using the thumb to trap objects between the thumb and the rest of the fingers.
I would suggest that you go to see your primary care doctor
. They will be able to confirm the diagnosis of carpal tunnel syndrome (and also consider other alternative diagnoses). If the diagnosis is carpal tunnel syndrome then rest of the wrist is essential. Additionally, splinting the wrist can prevent stress on the median nerve, and anti inflammatory medications can help improve the symptoms of pain and numbness.