Out of Control 3 year Old

My 3 Yr old is out of control and i dont know what to do?
He does not listen and hit me and his sister, screams constanly when he dont get his way and throws himself of the floor. he has punched me in the face and scrached me...he also says bad thing like he wants to kill me, or push me down the stairs and i would break my head open, he also to his sister he was going to break her arm.and thoes are just a few things he says... he also wants to play "doctor" alot and im not really sure if its normal or not? im real worried about him.

[Kevin Kennedy, Ph.D.]

No, this is not the normal behavior of a three-year-old. He should be evaluated by a mental health professional and you should seek some help re: parenting (particulalrly how to manage behavior). The more you can change the more he will change.