I have pain in my leg every night and can't sleep till 4-5am. even if i am sleepy or tired i still can't sleep?

Leg pain insomnia: One of the common causes of insomnia due to leg pain is restless leg syndrome. This can be caused by medications, be genetic, or due to medical conditions. If chronic - onset in childhood and no anemia - it is more likely rls. If recent onset, pursue a thorough medical evaluation. Any unpleasant sensation in feet, calves, thighs, arms or neck that disallows initiation of sleep can be rls.