Head Pain Back Of Head Hitting Why Do I Have A Pain In Upper Back Of My Head Come And Go?

Why do i have a pain in upper back of my head come and go? - head pain back of head hitting

Pain comes and goes and moves from right to left ....!
Only in the back of my head .. I do not know came to my head always remember .. nothing!
I'm afraid .... can someone tell me what to do with weight and weight that could be done ...?