My legs boss - my legs

Well, I've seem to have been woken up by severe leg cramps. Yes, ouch!  I sprang up out of bed and hobbled around for a moment wishing the pain would soon stop.  Luckily my legs obliged but now the muscles are fluttering not fully contracting but this so annoying that I can't sleep.  Just like any of you that is up past their bedtime, against their will, I ask - NOW WHAT?  lol