It’s 3 a.m. and you’ve been staring at your bedroom ceiling for nearly 2 hours, unable to sleep or get any rest at all. After what seems an eternity, you begin to feel yourself slip away, and drift off into a blissful slumber. After what feels like a blink, you’re awakened by sharp, agonizing cramps shooting through your legs and feet. Wincing in pain, the only relief you get is when you start moving your legs. Temporary relief comes, but at a cost – now, you’re fully awake again.