Symptoms of torn meniscus include abnormal knee flexion and extension, swelling, pain or joint cavity effusion, which need to be treated promptly. 1. Abnormal knee flexion and extension: when the meniscus is torn, it can lead to symptoms of limited knee movement, abnormal flexion and extension, and also interlocking of the knee joint. 2. Swelling and pain: it is one of the first symptoms, which may be due to local inflammation, resulting in congestion and other reactions in the knee joint, leading to pain. 3. Fluid in the joint cavity: when there is a meniscus tear, it may irritate the synovial membrane of the knee joint, resulting in excessive secretion, which leads to the symptom of fluid in the joint cavity. It is recommended to follow the doctor’s instructions for standardized treatment of meniscus tear, and not to deal with it blindly on your own, so as to avoid delaying the condition.