Why do i get leg cramps at night?

Many reasons..: You may be dehydrated or over exercising. You may have a vitamin or mineral deficiency. See your doctor and have an evaluation.

Very common: The majority of leg cramps simply occur from muscle deconditioning and overstretch, mostly occurring at night, and respond to stretching "toes toward the nose". Rare causes: low calcium or magnesium, neuromyotonia, restless leg syndrome, some drugs, familial, multiple sclerosis, pregnancy, strenuous exercise and some very, very rare neuromuscular diseases.