Numb pinky? happens alot what causes it?

Numbness to fingers/ hands generally occur to poor circulation to an area, e.g if you do sleep on your hand with any weight for a consistant time your hand or fingers will go numb. Normally takes up to 3 minutes to all numbness goes away with circulation being corrected. If it is that you may just have a poor blood pressure and bad circulation during the night, if its consistant consult a doctor, also try active sports