Hi,Doctor I Am Having Severe Pain In My Right And

Hi,Doctor i am having severe pain in my right and left legs to the front of my calf muscles extending towards my ankles .This occurs when I go to bed and is awaken with a cramping pain. This lasts for several minutes I am very concerned and would like to know what is i'ts cause and can I do for relief. Thanking you and is anxiously awaiting a reply.