what causes charley horses in legs

Charley horses in the legs are caused by muscle spasms or cramps, which are sudden involuntary tightening of muscles that can be painful and usually last seconds to minutes. Key causes include poor blood flow, muscle overuse or fatigue, dehydration, not stretching enough, electrolyte imbalances (such as low magnesium, potassium, or calcium), nerve compression, staying in one position for too long, and certain medications. Risk factors include older age, pregnancy, obesity, and conditions like diabetes or nerve disorders. These cramps often occur during physical activity or at rest, including sleep.