This is a symptom of abnormal sensation in the knee joint, which is directly related to the abnormalities of the nerves and blood vessels that control the tissues and structures around the knee joint, and requires consideration of whether the blood circulation around the knee joint is abnormal. The symptoms of coldness and chilliness. For example, in patients with lumbar disc herniation or lumbar transverse synovial syndrome, the nerves that control the sensation around the knee joint are squeezed and the nerve conduction is abnormal, which may cause the knee to sweat easily but the knee to feel cold. But the knee feels cold.