Foot cramps the next day calf is very painful common causes are catching a cold, muscle lactic acid buildup, muscle strains and so on. 1. Catching a cold: It may be that the feet and legs catch a cold when sleeping at night, and the blood vessels at the end of the feet contract, causing muscle tension and spasm, resulting in foot cramps, although the calves do not cramp, but also because of the cold, the next day, there is a pain phenomenon. 2. Muscle lactic acid buildup: In foot cramps, it will cause muscle contraction, spasm, and generally when the foot cramps, the calf muscles will also be pulled. As the muscle contraction during cramp will produce a lot of lactic acid, the next day because of the accumulation of lactic acid and calf pain. 3. Muscle strain: may foot cramp is not timely corrected, the cramp time is too long, muscle spasm is serious, so that the calf muscle strain, resulting in the next day the phenomenon of calf pain. Foot cramps the next day calf pain may have other reasons, it is recommended to pay attention to warmth in daily life, to avoid catching cold, and eat more calcium-containing foods.