It's a sign that your dehydrated.. Drink some water before bed every night, it ***** all the trips to the bathroom but it's better than waking up in pain from leg cramps.. As soon as I started drinking just a glass before bed I haven't had a single one and mine used to ce every night and were unbearable!!
You flex your toes up towards your knees. It should go away fast. Or stand in the cramped leg...but that requires getting out of bed. Works every time!
My doctor recommended vitamin c n it's been working well for me