The most common causes of knee pain and cold are rheumatoid arthritis, synovitis, osteoarthritis and so on. 1. Rheumatoid arthritis: this is an autoimmune disease, usually associated with heredity, infection, autoimmune and other factors, when rheumatoid arthritis acute attack will be easy to cause joint pain, swelling, the patient’s knee joints will be susceptible to cold stimulation. 2. Synovitis: Synovitis occurs when the synovial membrane of the knee joint is stimulated, usually related to acute and chronic injuries, joint degeneration, infections and other factors, and patients can show pain, joint swelling, and are prone to aches and pains and fear of cold. 3. Osteoarthritis: the specific cause is not clear, but usually with trauma, genetic and other factors, the patient can show pain in the knee joint, serious deformity of the knee joint, for cold stimulation is more sensitive. The causes of knee pain and fear of cold are more reasons, but also may be related to chronic strain, meniscus injury and other reasons, if the symptoms continue to have no relief, it is recommended to go to the hospital in a timely manner to find out the cause of the disease, by the doctor targeted treatment.