If it is a jumpy, ants crawling inside feeling..it is possible you should talk to your dr. about Restless Leg syndrome. Otherwise, it might be how you are sleeping. You could try putting a pillow under your legs and sleep on your back. Or sleep on your side with a pillow between your legs.
Hi Ruth, it could be the result of poor circulation or perhaps a pinched nerve in your back that can lead to sciatic pain in your leg. Please don't take this the wrong way because I'm not saying you are old, but even at my age, 47, I feel that things don't work like they used to. So I think the best thing is for you to go and get this checked out. Something that hurts bad enough to where you need to take painkillers is worth the trip to get a diagnosis. Best of luck.
arthritis? maybe dehydration. drink a lot of water