Coldness from the calves to the feet should be ruled out if there is a deficiency in the venous or arterial blood supply to the lower extremities, especially for male patients who are frequent smokers, and occlusive vasculitis needs to be ruled out. Unexplained occlusion or narrowing of the arterial blood vessels, resulting in blood supply obstacles below the calf, or slowing of blood flow, the patient will feel cold calves. In addition to vascular diseases, some patients with herniated discs and lumbar spinal stenosis, the sciatic nerve is compressed, which can also make the patient feel cold in the calves. In this case, an MRI should be performed to clarify the diagnosis, and attention should be paid to keeping warm in cold and wet weather. For the symptoms of sciatic nerve, giving mannitol dehydration, adenosylcobalamin nerve nutrition and other treatments can significantly relieve the symptoms.