What is knee pain at night? In our daily life, we often hear a lot of people say that the knee pain at night, the pain can not sleep and so on, especially in coastal areas more. So what’s wrong with knee pain at night when you sleep? The knee is a large and complex flexion joint in the human body. It is subject to high stress and has a stable and flexible structure. Knee pain occurs from time to time, and this pain is often ignored or arbitrarily thought to be arthritis and other conditions. In fact, there are still more reasons for knee pain caused by sleeping at night. Diseases that cause knee pain are mainly divided into five categories: 1, knee trauma or strain-induced diseases, such as meniscus injuries, ligament tears, traumatic synovitis and so on. 2, aging degenerative wear and tear diseases, such as osteoarthritis, chondromalacia patella and so on. 3, inflammatory diseases, such as gouty arthritis, rheumatoid arthritis, septic arthritis, joint tuberculosis and so on. 4.Tumor lesions, such as osteosarcoma, giant cell tumor of bone, bone metastasis, etc. 5, other diseases, such as pediatric knee joint growing pain, hip joint disease such as femoral head necrosis caused by knee joint pain. The most common clinical: knee trauma or strain, osteoarthritis of the knee joint in the elderly, rheumatoid arthritis. When knee pain occurs at night, first of all, you should pay attention to rest, reduce daytime activities, if there is an abnormality in time to consult a doctor.