Symptoms of cold legs and feet below the knee may be caused by prolonged standing and sitting, or by osteoarthritis of the knee, lumbar disc herniation, myofascial injuries and other factors. 1. Prolonged standing and sitting: standing or sitting for a long period of time will lead to poor blood circulation in the lower limbs, which will cause coldness and discomfort in the knees and below. 2. Osteoarthritis of the knee joint: overweight or incorrect exercise posture will lead to degeneration of the cartilage of the knee joint and osteomalacia and other aseptic inflammation, which will cause pain and swelling of the knee joint, and activities are affected by the symptoms of coldness of the lower limbs, calves and feet. 3. Herniated lumbar intervertebral disc: long-term stooping exercise will lead to degeneration of the lumbar intervertebral disc, which will compress the surrounding sciatic nerve and blood vessels, causing radiating pain in the innervated area, poor blood in the lower limbs, insufficient blood circulation in the muscles and other tissues, and insufficient nutrition and the occurrence of coldness in the area below the knee. 4. Myofascial injury: strenuous exercise without adequate preparatory activities before exercise will lead to myofascial and other soft tissue injury, resulting in an inflammatory response, which will cause the lower leg below the knee to the foot cold. Therefore, if the body appears below the knee calf to foot cold situation, it is recommended to go to the hospital orthopedic consultation in order to identify the cause of the disease, and actively carry out treatment.