Sore legs may be caused by lower limb vascular disease or muscle injury, which requires timely medical examination. The first thing to consider is that the arterial and venous blood supply is insufficient, commonly including arterial stenosis, plaque formation, varicose veins, thrombophlebitis, etc., resulting in insufficient blood supply to the lower limbs, which in turn produces such symptoms, and need to be timely for the arterial and venous ultrasound of the two lower limbs. In addition, it may also be due to sports or heavy physical labor, resulting in lower limb muscle injury, such as muscle strains, etc., fail to take the correct relief method in time, and gradually develop into chronic injury. Legs have been sore for a number of reasons, may also be caused by lactic acid buildup, generally can be relieved after rest, if it is difficult to relieve, need to consult a doctor in a timely manner, under the guidance of the doctor for targeted treatment.