What are the causes of knee pain and swelling? We usually have to use the knee joint when we exercise or walk. The knee joint is a stable and flexible structure that carries the weight of the upper body. What are the causes of knee pain and redness? 1, ligament rupture In the event that the activity exceeds the range of the joint can withstand, the surrounding ligaments will be torn due to passive pulling. When the exercise is accompanied by fractures and sprains, the tissue damage caused by external forces will be accompanied by pressure, pain and swelling, and the movement will be limited and cannot be fully straightened. 2. Septic arthritis Septic arthritis is usually caused by bacteria that infect the joints of patients, usually in children, and is a complication of leukemia. Septic arthritis is also caused by traumatic joint infections or surgical infections, which can cause severe pain in the joints and restrict movement. The joints may become red, swollen, and painful at the onset. Deeper joints may become swollen when they are involved. Synovitis is a multiple disease, mainly in the knee joint, because the patient’s knee joint is sprained or injury caused by the disease, usually occurs in young adults, when the injury will have mild edema and pain in the knee joint, activity will be limited, walking instability. Eight hours after the injury, there is a reactive fluid accumulation, and the knee joint is visibly swollen and hot, and it is difficult and painful to touch it and squat. 4, rheumatoid arthritis rheumatoid arthritis and the autoimmune system has a direct relationship, belongs to the chronic disease. Patients in the early stages of the joint will appear local pain, especially when the activity will be accompanied by pressure pain and tenderness. When the inflammation involves the soft tissues around the joints, there is diffuse swelling and the surface temperature increases. Tips: Being overweight can increase the pressure on the knee joint, and obese people should reduce their weight. Lack of exercise can cause the muscles to atrophy and not protect the joints and bones better, thus increasing the pain. It is recommended to choose yoga, walking or swimming, which not only activates the muscles, but also improves the body’s balance. Avoid high-intensity exercises, such as repeated squats and stair climbing and mountain climbing, which can increase the pressure on the knee joint. Cold compresses can be applied within 48 hours after the injury to reduce swelling and pain, and hot compresses can be applied after 72 hours to promote the absorption of inflammation.