What could cause me to get severe pain in my calf muscles?

Check labs and shoes: Make sure to check serum electrolytes , particularly potassium. Dehydration is a common cause, so check urine color, it should be light yellow. Gait can cause unusual strain on these muscles, so check your shoes for uneven wear. If needed , see a podiatrist for shoe orthotic correction.Venous thrombosis, or clots, are unusual in both legs, but look for redness , or swelling of the legs.