A change in the day on the leg pain refers to weather changes in the lower limbs after the pain, common causes are: cold, knee osteoarthritis, rheumatoid arthritis, diabetes complications. 1. Cold: If you don’t pay attention to warmth after the weather gets cold, the lower limbs get cold and the blood circulation slows down, and then there is pain in the lower limbs, which is a normal phenomenon. 2. Osteoarthritis of the knee joint: due to old age, obesity, trauma and other reasons, causing osteomalacia of the knee joint and destruction of articular cartilage, which can cause knee pain, and can induce or aggravate knee pain after the weather becomes cold. 3. Rheumatoid arthritis: it is an autoimmune disease that can occur in many joints of the body, including ankle joints and knee joints of the lower limbs, due to the attack of immune cells on the normal tissues, causing joint pain, which can be triggered or aggravated by a drop in temperature. 4. Diabetic complications: poor long-term blood sugar control, resulting in peripheral vascular disease, arterial plaque formation, poor blood circulation in the lower extremities, blood circulation disorders aggravated by the cold weather can induce or aggravate pain in the lower extremities. Causes of pain in the lower limbs after the weather changes are more reasons, may also be related to ankylosing spondylitis, lumbar disc herniation, varicose veins in the lower limbs and other diseases, if the symptoms continue to be unrelieved, it is recommended to consult a doctor in a timely manner, to clarify the cause of the disease, and targeted treatment.