Patients with cold thighs, to consider two situations, as follows: First, vascular causes: the existence of vascular diseases of the lower limbs, such as lower limb occlusive vasculitis, often occurs in the veins, arterial occlusion, the lower limb blood supply is reduced, so there will be a cold lower limbs, and there will be intermittent claudication, cold pain in the lower limbs and so on. In this case, it is necessary to go to the ultrasound examination of the blood vessels of the lower limbs at an early stage to make it clear whether there is any vascular disease. Second, neurogenic causes: generally due to the sciatic nerve or spinal nerve compression, when the nerve compression, can cause lower extremity radiating pain and numbness. However, some patients can show abnormal sensation in the lower limbs, which can be manifested as localized chills, which should be clarified by lumbar spine MRI and CT examination.