Some patients feel swollen knee joints and calves, fear of cold; squatting up with difficulty; walking knee pain, can not walk fast; and even some patients have creaking sound inside the knee joint, these are all symptoms of synovitis. There are many causes of synovitis, such as walking, standing for a long time, catching a cold, getting injured, and so on. Usually it will be fine after a few days of rest. However, there are some patients who have had synovitis for a long time and are still not well, so it is important to be aware that there may be other problems with the knee. This means that it is not just a simple synovitis. The knee joint is like a precision bearing with cartilage, meniscus and ligaments, and the synovial membrane is only one part of it that is lubricated. We commonly see many patients with meniscal and cartilage injuries who have been treated for synovitis, often with poor results. If the synovitis does not heal over time, it is possible that there is something wrong with other structures in the joint, and it is necessary to come to a major hospital to see an experienced doctor and have some imaging done to find the real cause of the synovitis.