Posterior hamstring pain refers to muscle and tendon pain in the posterior side of the lower limb, and the possible causes are sports injury, trauma, varicose veins of the lower limb, fasciitis, calcium deficiency and so on. 1. Sports injury: not warming up sufficiently before exercise or too much exercise, resulting in muscle strain and lactic acid accumulation, which can cause pain in the muscles and tendons of the lower limbs. 2. Trauma: most of the lower limbs have a history of trauma, the role of violence leads to soft tissue injuries in the legs, can also appear muscle, tendon pain, swelling and other symptoms. 3. Varicose veins of lower limbs: due to varicose veins of lower limbs caused by standing for a long time, developmental abnormality, pregnancy, etc., blood reflux is blocked, and superficial varicose veins can be seen locally, flexing into a mass, and swelling, pain, fatigue, and hyperpigmentation of lower limbs can occur. 4. Fasciitis: due to trauma, strain, immunization, etc., it causes aseptic inflammation of the legs, which is manifested by pain, muscle tension and other symptoms. 5. Calcium deficiency: If calcium and vitamin D intake is insufficient, the nerve excitability of muscles increases after calcium deficiency, and leg twitching and pain can also occur. There are more causes of muscle and tendon pain on the back side of the lower limbs, if the symptoms continue to be unrelieved, it is recommended to consult a doctor in time to clarify the cause of the disease and carry out targeted treatment.