The following reasons can be considered when the knee hurts when pressed: First, synovitis: if the pain around the knee hurts when pressed, it is generally considered to be caused by synovitis. The pain caused by synovitis is diffuse pain, and there is no fixed pain point in the knee joint, so as long as the pressure around the knee joint may cause pain. Secondly, osteoarthritis and meniscus injury: if it hurts when pressed in a specific part of the knee joint, for example, it hurts when pressed in the medial gap of the knee joint, it can be considered as degenerative osteoarthritis of the medial gap, and it can be considered as medial meniscus injury, and it should be evaluated and judged by MRI examination and X-ray examination. Third, other diseases: if it is painful to press the back of the knee joint, it can be considered as popliteal cyst or inflammation and contracture of the posterior ligament, which can cause posterior pain.