Why do i have "charlie horses cramps in the calf of my leg that wakes me up while i am sleeping never had this before am very active and 70 years old woman

Nighttime : Nighttime leg cramps are involuntary, painful contractions of muscles in the lower limbs. These cramps usually affect the calves, but can also affect the feet and toes. While they are usually benign, there are some cases when cramps can be an indication of a serious problem, like circulatory disease, diabetes, thyroid disease, parkinson disease, vitamin deficiency, effects of medication, or a pinching of a nerve or nerves in the spine or lower limb. New onset of leg cramps is a good reason to visit a doctor to sort things out and (hopefully) get back to normal sleep.