Posterior calf pain after running may be caused by muscle strain, lactic acid accumulation, varicose veins of the lower limbs and other reasons. It can be treated by hot compress, massage, medication, surgery and other methods according to different causes. 1. Muscle strain: Improper exercise methods or excessive exercise intensity can lead to pain in the back of the calf after running, you need to pause running and other leg exercises, after a period of rest can be relieved by rest, massage and other methods. At the same time, you can also elevate the calf, promote blood circulation in the leg, reduce the pain. Severe pain can be oral anti-inflammatory analgesic drugs, such as ibuprofen. 2. Lactic acid accumulation: prolonged exercise can lead to lactic acid accumulation in the back of the calf, resulting in soreness and pain in the back of the calf. You can accelerate the blood circulation in the calf through hot compresses and massages to promote the dissolution of lactic acid accumulated in the back of the calf, so as to achieve the effect of relieving pain. 3. Varicose veins of the lower limbs: Varicose veins of the lower limbs can cause insufficient blood supply to the legs after exercise, resulting in numbness and swelling pain. Patients can use compression stockings for treatment and prevention. Surgery may be considered in severe cases. When doing other exercises such as running, one should take a gradual approach and avoid strenuous exercise for a short period of time. If the pain cannot be relieved or is accompanied by other symptoms, it is recommended that the patient seeks medical attention for a clear diagnosis and professional treatment.