arthritis, painful inflammation of a joint or joints of the body, usually producing heat and redness. There are many kinds of arthritis. In its various forms, arthritis disables more people than any other chronic disorder. The condition can be brought about by nerve impairment, increased or decreased function of the endocrine glands, or degeneration due to age. Less frequently, it is caused by infection (tuberculosis, gonorrhea, Lyme disease, rheumatic fever).

Rheumatoid arthritis, an autoimmune disease of unknown cause, is the most crippling form. Women are much more susceptible to it than men. Although rheumatoid arthritis usually appears between the ages of 25 and 50, it also occurs in children. Osteoarthritis, the most common type, occurs usually in people over 50. It tends to be more severe when the joints have been strained by obesity or overwork. Gout, the third most common form of arthritis, affects men almost exclusively.

Symptomatic treatment for arthritis includes use of heat, physical therapy, and nonsteroidal anti-inflammatory drugs such as a cox-2 inhibitor (Celebrex), aspirin, ibuprofen, and naproxen. Remission of symptoms can sometimes be achieved with methotrexate, gold salts, penicillamine, and short-term cortisone, but they often have undesirable side effects. Orthopedic surgery, including artificial joint implantation, may be done in severe cases.

Acute inflammation of one or more joints caused by infection. Suppurative arthritis may follow certain bacterial infections; joints become swollen, hot, sore, and filled with pus, which erodes their cartilage, causing permanent damage if not promptly treated by giving antibiotics, draining the pus, and resting the joint. Nonsuppurative arthritis can accompany several diseases caused by bacteria, viruses, or fungi; joints become stiff, swollen, and painful to move. Treatment includes rest, drugs, and, in the case of tuberculosis, orthopedic care to prevent skeletal deformity.

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Chronic, progressive autoimmune disease causing connective-tissue inflammation, mostly in synovial joints. It can occur at any age, is more common in women, and has an unpredictable course. It usually starts gradually, with pain and stiffness in one or more joints, then swelling and heat. Muscle pain may persist, worsen, or subside. Membrane inflammation and thickening scars joint structures and destroys cartilage. In severe cases, adhesions immobilize and deform the joints, and adjacent skin, bones, and muscles atrophy. If high-dose aspirin, ibuprofen, and other NSAIDs do not relieve pain and disability, low-dose corticosteroids may be tried. Physical medicine and rehabilitation with heat and then range-of-motion exercises reduce pain and swelling. Orthopedic appliances correct or prevent gross deformity and malfunction. Surgery can replace destroyed hip, knee, or finger joints with prostheses. There is also a juvenile form of the disease.

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Inflammation of the joints and its effects. Acute arthritis is marked by pain, redness, and swelling. The principal forms are osteoarthritis, rheumatoid arthritis, and septic arthritis. Several forms of arthritis are part of the symptom complexes of autoimmune diseases.

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