Cold and numb hands may be caused by environmental factors, arteriosclerosis and diabetes. 1. Environmental factors: may be due to the patient in a cold environment for a long time, resulting in peripheral vasoconstriction, so that the peripheral blood circulation is not smooth, thus the symptoms of cold hands and numbness. 2. Arteriosclerosis: it may be due to the narrowing of local blood vessels caused by arteriosclerosis, which results in impaired blood circulation in the endings of the hands, leading to the symptoms of cold and numb hands. 3. Diabetes mellitus: patients with this disease, especially those with long-term blood sugar instability, may have cold and numb hands, and if this symptom occurs, we should be alert to the occurrence of diabetic peripheral neuropathy. Therefore, if the patient appears to have serious symptoms of cold and numb hands or accompanied by other symptoms of the disease, should go to the hospital in a timely manner to avoid delays in the condition.