Waking up with bruises

Alright when I was younger I would wake up with bruises and scratches and in come cases i'd wake up with busted lips or nose bleeds. After a while I stopped waking up like that but recently its started up again. 
 
I have MANY bruises all over me. I had them on my legs, my chest, my stomach, my shoulders knees...I have no Idea why.. I wake up with awful headaches,  and covered in bruises. WHY me!?
 
Why does it happen?