CRAMPS?!!!!!!!!

Hey ladies for about a week now I have been getting really bad cramps in my calfs all night long they r preventing me from sleeping! Any ideas on if it can be a medical issue I read that it can be dehydrated r also low blood supply so certain area during pregnancy. I have had them when I was younger but I just ate bananas and it would go away but that hasent been helping me. I ask about dehydrated because I had low fluid levels last time I was checked and catch myself not drinking during the day like I should. Any advice?