Cold weather irritation, causing knee pain, may have primary diseases, such as meniscal injury, synovitis, knee osteoarthritis, osteoporosis, etc. 1, meniscus injury: long-term weight bearing, degenerative disease of the bone and joint of the elderly make meniscus injury, after cold, resulting in pain in the knee joint area; 2, synovitis: cold stimulation impede blood circulation, resulting in sterile inflammation, erosion of joint cartilage to limit joint movement, swelling around the joint, pain symptoms; 3, knee arthritis: degenerative disease of the knee joint, overexertion leads to knee arthritis, inflammation stimulation Inflammatory stimulation causes congestion and edema in the knee joint, and pain is aggravated by cold, resulting in restricted movement; 4, osteoporosis: calcium loss causes osteoporosis, and mutual friction between joints leads to knee pain. In addition, osteophytes are also one of the causes of knee pain; 5, rheumatoid arthritis: knee pain after cold may also be an early sign of rheumatoid arthritis, it is recommended that patients seek medical attention in a timely manner, in the Department of Rheumatology and Immunology to investigate the presence of rheumatic diseases. In addition to treating the pain, if you want to improve the symptoms of knee pain caused by cold weather, you should also pay attention to keeping warm in daily life, avoid weight bearing, prevent further aggravation of symptoms by wearing knee pads and avoiding getting cold in the wind, and exercise appropriately to enhance physical fitness and improve blood circulation. If the symptoms are severe, you can consider medication with acupuncture and physiotherapy, or surgery if necessary, to prevent movement dysfunction with limited joint movement.