<s>[INST] What Is Arthritis? [/INST] The word arthritis literally means joint inflammation, but it is often used to refer to a group of more than 100 rheumatic diseases that can cause pain, stiffness, and swelling in the joints. These diseases may affect not only the joints but also other parts of the body, including important supporting structures such as muscles, bones, tendons, and ligaments, as well as some internal organs. This booklet focuses on pain caused by two of the most common forms of arthritis--osteoarthritis and rheumatoid arthritis. Source: NIAMS. Link: https://webharvest.gov/peth04/20041015190953/http://www.niams.nih.gov/hi/topics/arthritis/arthpain.htm. Field: Rheumatology. Disease: Arthritis </s>