Even though the word "arthritis" literally means "joint inflammation," it's also used to refer to 200 different conditions that affect the connective tissues around joints, as well as other joints and tissues. It is a rheumatic disorder. Osteoarthritis is the type of arthritis that is most prevalent. Gout, fibromyalgia, and rheumatoid arthritis are three other common rheumatic conditions associated with arthritis (RA). Rheumatic diseases are characterized by pain, aching, stiffness, and swelling in and around one or more joints. Symptoms can appear gradually or suddenly. Certain rheumatic conditions can also affect the immune system and other internal organs.