There are many possible reasons for the cold calf stomach, lower extremity arteriosclerosis, vasculitis, arteritis, arterial spasm, varicose veins of the lower extremities, peripheral nerve disease, hypothyroidism and so on can cause cold legs and stomach. 1. Lower extremity arteriosclerosis: mainly because of arteriosclerosis, the formation of plaque can block blood vessels, causing lower extremity arterial ischemia or infarction, which leads to cold calves. 2. Vasculitis, arteritis, arterial spasm: Inflammation and spasm of large and small arteries in the lower limbs, such as vasculitis, arteritis, arterial spasm, etc., lead to poor blood supply, which will result in the symptom of coldness in the lower limbs. 3. Varicose veins of the lower limbs: the most common is varicose veins of the saphenous vein, which will lead to obstruction of venous return in the lower limbs and poor blood circulation, causing symptoms of cold legs and stomach. 4. Peripheral nerve diseases: such as lumbar disc herniation, pyriformis syndrome and other compression of the sciatic nerve so that the lower limbs have sensory abnormalities, there may be a cold feeling in the legs and stomach. 5. Hypothyroidism: caused by reduced secretion of thyroid hormone, which can lead to lower metabolism and lower sympathetic excitation, manifesting as coldness, fatigue, indifference, slow reaction, rough skin, constipation, and so on. The disease can be clarified when thyroid function tests are performed, which generally show a decrease in T3/T4 and an increase in TSH. The most common cause of this condition is Hashimoto’s disease (chronic lymphocytic thyroiditis). There are many causes of cold legs and stomach. If it cannot be relieved after rest, persists for a long time, or is accompanied by other discomforts, it is recommended to consult a doctor in time to clarify the diagnosis and further treatment.