I managed to get all by blood test results which I had over the last few months..I noticed my ESR levels are 45, the range should be between 0-10,this has slowly been climbing for the last few years..is this a cause for concern

This is a test for inflammation and there are things that can effect results like anemia. I would think your doctor would pay some attention to this. On its own it doesn’t give you a diagnosis but it may help your doctor to pursue tests in that direction. It’s not a cause for concern, just information. I think the more data you can get the better chance you have of finding a cause. :)

Everything else is fine just my ESR and CRP is on the high end of the range 5(noraml range between 0-5)is this something I should mention to my GP to investigate?

I would. In my experience most doctors aren’t concerned if you're in range. I happen to disagree with that practice. Regardless, it wouldn’t hurt to ask even if it’s just for your piece of mind. There are others in this group that would know this answer better then me. Perhaps one will jump in. :)