Swelling pain in the leg belly may be physiological reasons, or pathological reasons, such as lower extremity venous thrombosis, gastrocnemius muscle strain, lumbar intervertebral disc herniation, pear-shaped muscle syndrome, calcium deficiency and other diseases. 1. Physiological reasons: if standing for a long time can cause swelling and pain in the legs. Lower limb elevation and rest can reduce. 2. Lower extremity venous thrombosis: Lower extremity venous thrombosis causes poor blood return to the lower extremities, resulting in swelling and pain. 3. Gastrocnemius muscle strain: Strenuous exercise or walking too much caused by calf gastrocnemius muscle strain, muscle swelling and pain, through massage, hot compresses, etc., the symptoms can be reduced. 4. Lumbar disc herniation: the herniated disc can radiate to the calf swelling and pain by compressing the nerves. It can be clearly diagnosed through MRI film. 5. Piriformis syndrome: piriformis muscle compression of the sciatic nerve can cause pain in the back of the thigh and calf, aggravated by walking. 6. Calcium deficiency: Calcium deficiency can also cause calf pain, some will have leg cramps. There are many reasons for leg pain, if rest does not reduce, go to the hospital to check, clear cause for treatment.