Calf belly cramps and pain are mainly caused by the corresponding dysfunction of the calf muscle groups, resulting in involuntary and violent spasms and contractions of the muscle fibers, thus producing the corresponding cramps and pain symptoms. The common causes include the following: 1, poor local blood circulation, including cold, local inflammation, varicose veins, phlebitis, and local swelling occupancy, compression, can affect the blood supply of muscle groups, resulting in relative muscle ischemia, hypoxia, dysfunction, cramps, pain symptoms. 2, visible in the muscle itself, such as muscle injury, strain, and muscle outside the tendons.