There are three basic types of arthritis that may affect the joints. Generally, the pain associated with arthritis develops gradually, although sudden onset is also possible. The joint may become stiff and swollen, making it difficult to bend or straighten the knee. Pain and swelling are worse in the morning or after a period of inactivity. Pain may also increase after activities such as walking, stair climbing, or kneeling. The pain may often cause a feeling of weakness in the knee, resulting in a "locking" or "buckling". Many people report that changes in the weather also affect the degree of pain from arthritis. Please use the links provided to learn more.