Severe foot and leg cramps can be the result of magnesium or potassium deficiency, problems with blood circulation in the legs, nerve malfunction, dehydration and muscle fatigue, among other conditions, according to WebMD. They can also be a side effect of certain medications, such as Lasix, Aricept and Procardia.
Muscle cramps may also be exercise related, resulting from inadequate stretching before exercise, over-exertion of the muscle while exercising or exercising in the heat, explains WebMD. In pregnant women, leg and foot cramps can be the result of a calcium deficiency. To help ease a muscle cramp, sufferers can try massaging the muscle, warming or icing the muscle, stretching or taking a bath with Epsom salt.