It is not recommended to judge whether the meniscus of the knee is damaged or not by yourself, you should go to the regular hospital to be judged by the doctor, usually using the rotary compression test, MRI and other judgments. The cause of meniscus injury is usually trauma, such as fall from height, fall when the knee hit the ground impact injury; may also be due to strenuous exercise knee joint damage; the elderly due to osteoarthritis, degeneration of the joints may also lead to meniscus wear and tear; developmental abnormality of the child, there may be abnormal development of the meniscus, the disc-shaped meniscus. To determine whether the meniscus is damaged, the meniscus can be damaged by the rotary compression test, i.e., letting the knee joint be in a semi-flexed position, twisting the knee joint, and if obvious pain occurs, there may be damage to the meniscus; if there is severe swelling of the knee joint, limited movement, subcutaneous ecchymosis and other symptoms, there may also be damage. In addition, MRI can also be used as an adjunctive examination to determine whether damage exists. To determine whether the meniscus is damaged, it is recommended to go to a regular hospital for a comprehensive judgment by a professional doctor and take treatment measures if necessary.