Synovitis occurs in children as well as in middle-aged and elderly patients. Pediatric synovitis should be treated in a timely manner, as delaying the condition can lead to significant sequelae, especially in the later stages of synovitis, which can lead to adverse joint movement even if cured, and can easily lead to chronic synovitis, with pain on the affected side due to changes in weather. Synovitis in middle-aged and elderly patients is mostly due to injury and degenerative changes in the joints. Synovitis has fewer sequelae, except for knee pain and wear and tear of the articular cartilage, and does not have major sequelae, so middle-aged and elderly patients should pay attention to keeping warm and avoiding excessive joint activity that can trigger synovitis.