In the middle of the night, you're jolted upright from a sound sleep. Your calf muscle hurts, and it's squeezing tighter. They don't cause damage, but they hurt.
All muscles are subject to cramping, but the leg muscles are most susceptible.
Doctors don't know exactly why muscle cramps occur. But they tend to occur after muscle fatigue, dehydration or injury. Simply remaining in the same position for a prolonged time may contribute to a cramp, Dr. Knochel says. But Dr. Knochel adds that cramps affect almost everyone at some time in their lives. Electrolytes are minerals that permit the body's cells to exchange fluids properly.