Cold knee pain is mainly considered to be caused by the presence of fluid and sterile inflammation in the knee joint, the presence of fluid will lead to cold performance, sterile inflammation will lead to pain, consider the following possibilities: 1, osteochondritis of the knee joint, especially seen in young patients after strenuous exercise, after strenuous exercise due to more obvious wear and tear of cartilage, and osteochondritis, and induced joint fluid, that is, fluid. 2, Knee meniscus injury, often patients have a history of obvious trauma, too frequent exercise and sprains, some patients appear obvious card pressure, causing local bleeding, edema, resulting in painful chills. 3, knee synovial crease syndrome, which is a soft tissue lesion, with increased exercise, knee degeneration, chronic wear and tear stimulation, synovial hypertrophy within the knee joint and edema, synovial 4. rheumatoid arthritis, which is an immune system disease, that is, the deposition of immune complexes in the joints caused by early synovial lesions, and eventually become arthritis, in the accumulation of fluid will appear obvious edema.