Leg cramp pains?

How long do they normally last and how bad do they feel? Got my first one ten minutes ago and elevating my leg feels like it's on fire.... I know I'm probably panicking I just don't feel too great over all today (spent most of it in the hospital for adopt.sister) probably paranoid just need some reassurance and the fiancé is super tired so he can't coherently make a sentence without falling back to sleep twice in the process.