My calves cramp every evening ㅠㅠ

My calves cramp occasionally when I lie down to sleep in the evening ㅠㅠ

Is this the early stage of varicose veins!??

Or maybe it's just something like swelling..?!?

Even on days when I don't overexert myself with exercise during the day, it happens once in a while.

How can I prevent leg cramps while sleeping?

Would it be okay if I rub my leg with a foam roller!?? ㅠㅠ