What causes leg and calf cramps at night

Imagine you’re lying down and your lower leg seizes. The pain is intense enough to make you want to scream. It doesn’t let up and your muscle is hard to the touch. When you try to move your leg, it feels paralysed. Sound familiar?

Sometimes referred to as muscle spasms or charley horses, they occur when one or more of the muscles in the leg tighten involuntarily.

Leg cramps most often affect the gastrocnemius muscle (calf muscle) which spans the back of each leg from the ankle to the knee. However, they can also affect the muscles at the front of each thigh (quadriceps) and the back of each thigh (hamstrings).

You can be awake or asleep when a leg cramp strikes. Most of the time, the muscle relaxes itself in less than 10 minutes. Your leg might feel sore or tender for up to a day afterward. Frequent calf cramps at night can disrupt your sleep.

Leg cramps during sleep are more common among women and older adults.