Swollen knees need to be treated according to the condition, which may be caused by trauma, meniscus injury or fracture in the knee joint, and the treatment includes conservative and medication. 1. Trauma: the first cold compresses can relieve the symptoms of edema and pain, and after 72h, local hot compresses and more rest. 2. Meniscus tear in the knee joint: knee arthroscopy can be considered as a treatment. 3. Fracture: if the knee is injured in a fall, if there is obvious swelling, it means that there is a lot of local bleeding, and there may be patellar fracture or intra-articular fracture of the knee, if the patellar fracture is not obviously displaced, you can wear a knee brace. If the above symptoms occur, it is recommended to go to the hospital in time.