What causes leg cramps at night?

Leg cramps at night may be caused by the following reasons: 1. Calcium deficiency: Calcium ions play a crucial role in muscle contraction. A lack of calcium in the body can increase neuromuscular excitability, leading to nocturnal leg cramps. 2. Cold exposure: During the night, lower temperatures may cause the legs to become chilled if proper warmth is not maintained. This chilling can trigger blood vessel constriction, impair local blood supply, and subsequently induce leg cramps. 3. Excessive fatigue: After intense physical activity or strenuous labor during the day, leg muscles may remain fatigued, which can result in leg cramps during nighttime rest. 4. Improper sleeping posture: Maintaining a certain position for prolonged periods—such as placing continuous pressure on the legs—can also lead to nocturnal leg cramps.