Soreness and distension of the right calf and normal left leg may be caused by physiological factors such as exercise and fatigue, or it may be caused by pathologic factors such as lumbar intervertebral disc herniation, varicose veins of the lower limbs, osteoarthritis, and so on. 1. Physiological factors: Excessive movement of the right leg, long walking and other factors can cause calf muscle fatigue and accumulation of lactic acid in the body, which can cause the symptoms of soreness and swelling in the right calf. 2. Herniated lumbar intervertebral disc: Herniated intervertebral disc can compress the nerve root of sciatic nerve on one side, which will cause the phenomenon of right calf soreness and swelling on the left side of the body, and at the same time it can be accompanied by numbness of the lower limbs. 3. Varicose veins of the lower limbs: Varicose veins of the right lower limbs may cause poor blood circulation in the lower limbs, resulting in soreness and distension of the right calf and normalization of the left leg. 4. Osteoarthritis: Osteoarthritis of the right knee, due to degenerative lesions and inflammation stimulation, can cause soreness and swelling of the right calf, as well as activity limitation. Caused by the right calf soreness and distension of the left leg normal, there may be other reasons, it is recommended to timely hospital consultation, improve the examination to clarify the cause of the disease, under the guidance of the doctor for standardized treatment.