Cramps occur in the morning for the following common reasons: 1. As a result of night sleep, the cramped limb suffers from extrusion or local cold, resulting in poor local blood circulation and the accumulation of metabolites within the muscles. In the morning, the stimulation of metabolites, together with the contraction of muscle activity, leads to dysfunction, resulting in cramping symptoms. 2. During night sleep, the body’s overall metabolic rate, blood pressure, and circulation are reduced. In the morning when you get up due to too much activity, it will lead to local blood circulation nutrients can not keep up, there is a short period of muscle hypoxia, ischemia, and thus cramps symptoms. The reasoning is similar to that of not warming up well before exercise, which can lead to cramping symptoms during exercise.3. After a night’s sleep, patients may have low blood sugar, low calcium ions and low potassium ions when they get up in the morning. These changes in the internal environment can affect muscle function, which can easily lead to muscle function disorders during activity, resulting in cramping symptoms.