The lumbar region is very cold to consider dermal neuritis, lumbar disc herniation, catching cold, cerebrovascular disease, diabetic neuropathy and other reasons. 1. Dermal neuritis: due to trauma, infection, poisoning and other reasons, resulting in dermal neuritis, lumbar dermal nerve innervation area of the sensory impairment, the feeling of cold, with the hand to touch the temperature is normal. 2. Lumbar intervertebral disc herniation: when the nucleus pulposus protrudes and compresses the posterior branch of the spinal nerve, local sensory loss occurs and a cooling sensation appears. 3. Cold: when the indoor environment is too low, blowing a fan or air conditioning is likely to cause the skin to feel cold, and the symptoms will be reduced after keeping warm. 4. Cerebrovascular disease: for example, cerebral infarction, cerebral hemorrhage will cause one side of the sensory loss, such as waist or lower limbs numbness, cold. 5. Diabetic neuropathy: long duration of diabetes will appear nerve damage, sensory impairment, local sensory cold. The waist is very cold need to go to the hospital for examination and treatment after clarifying the cause of the disease.