Pain on the second day of midnight calf cramps is mainly due to damage to the muscles in the calf area due to violent spasms in the midnight cramps. Especially in patients who have had cramps for a long period of time, this condition is followed by the formation of slight local damage, bruising and inflammatory edema. The pain is more pronounced on the second day because the accumulation of metabolic products is not enough on the night of the cramp, but on the second day the accumulation of metabolic products gradually increases and stimulates the peripheral nerves, so that the pain is more pronounced on the second day. The calf cramp must be relieved immediately after the appearance of the calf, usually choose to let the calf part of the muscle is stretched, so as to effectively relieve, such as the back of the calf cramp must let the ankle joint in dorsal extension state muscle can be stretched, the longer the cramp pain symptoms will be heavier. And be sure to pay attention to the warmth of the cramp position, not to appear cold, after the cold easily induced leg cramps again, will also lead to the accumulation of local metabolites more and more pain symptoms more obvious.