Below the meniscus is the cartilage around the knee, and pain below the meniscus is also pain in the cartilage around the knee. The specific cause may be inflammation around the cartilage or tearing and straining of the ligaments around the cartilage of the joint. 1. Inflammation around the cartilage: Inflammation of the cartilage tissue may be due to the cartilage part of the violent collision, resulting in localized damage. It may also be due to cold joints, inflammatory metabolites attached to the surface of the cartilage, inflammatory metabolites gradually build up, resulting in inflammation, causing pain. 2. Perichondral ligament tears and strains: most patients have a history of sports injuries. Injuries to the articular cartilage and periarticular ligaments and tendons during sports can cause pain below the meniscus. If there is localized effusion, swelling may also occur. If the damage is not severe, warm compresses and physical therapy may be the mainstay; if the damage is more structural, arthroscopic surgery may be required to heal the injury. If the pain is below the meniscus, it is recommended that the patient go to the hospital for a CT scan of the knee to diagnose the cause and take appropriate treatment according to the results of the test.