For causes of cold knees, specifically as follows: First, degenerative arthritis of the knee: in the degeneration of the joint, there is often chronic pain, especially after the invasion of cold or weight-bearing activities, the pain will be particularly pronounced, so in the process of joint degeneration, often use heat to do as an effective means of treatment, heat can make the knee joint vasodilatation, improve blood circulation, thereby relieving pain. Second, vascular diseases of the lower extremities: such as lower extremity occlusive vasculitis, mainly due to arterial occlusion, which can cause a reduction or interruption of the blood supply to the lower extremities, often leading to cold pain in the lower extremities, which can be manifested as cold, painful knee joints, calves, feet, and in severe cases, intermittent claudication of vascular nature.