It happens without warning, and it can happen at any time: when you are exercising, when you are sleeping, or when you are simply going about your day. Your calf suddenly seizes up, turning hard as a rock and hurting like crazy. If you’ve ever had one, you know that this description is referring to a charley horse. But what causes charley horses? More importantly, how can you stop them when they happen and prevent them from coming back?
What is a charley horse?
“A charley horse is a muscle spasm or a cramp in your lower leg, and it’s often acutely painful,” said Daniel Probst, M.D., a Summit Orthopedics physical medicine and rehabilitation (PM&R) specialist. “The muscle gets caught in a cycle of tight contraction, which causes pain.”
Doctors don’t know for sure what causes charley horses, and it varies from person to person. Historically charley horses were thought to be caused by electrolyte imbalances and dehydration. However, there is growing evidence that muscular fatigue and poor neuromuscular endurance can cause charley horses. Some medications or medical conditions can make charley horses more likely. They are also more common among athletes and pregnant women. In some cases, they may be caused by an imbalance of electrolytes in the body.