Why do we get muscle cramps?

A cramp is a sudden, sustained, and often painful tightening of a muscle that will not relax. Many cramps happen because overworked or fatigued muscles begin firing erratically, especially during or after intense exercise. Dehydration and low levels of electrolytes such as sodium, potassium, calcium, and magnesium can also disturb the electrical signals that control muscle contraction, making cramps more likely. Poor circulation, staying in one position too long, and certain medications can trigger them as well. Nighttime leg cramps are common in older adults. Most cramps ease within minutes and can be relieved by gently stretching and massaging the affected muscle, which helps reset the overactive nerve signals.