Arthritis is inflammation of any joint, and it can be traced to infectious, metabolic, or constitutional causes in adults or to heredity in young people. Thus, came the term arthr- or arthro–, which is the Latin combining form meaning "joint," and–itis, indicating inflammation. One or more joints become painful, stiff, and less functional or nonfunctional. The Arthritis Foundation, the chief nonprofit U.S. organization dedicated to making arthritis better understood and better treated, recommends that professional help from a physician be sought whenever pain, swelling, or trouble moving a joint persists for more than two weeks. During that time, physicians recommend that patients relieve their pain with aspirin or ibuprofen.
Blood tests for arthritis are not always conclusive. Patients with rheumatoid arthritis may have normal results. X-ray examinations may show change or variations from normal, scoliosis, less joint space, spurs, or what physicians call tophi. Tophi are chalky deposits that form around joints and cause the body to respond as it does to any foreign invader–with inflammation. These deposits, made of sodium urate and characteristic of gout, may be found in tissue or bursae, those fluid-filled sacs meant to prevent friction near bone, as well as in cartilage or bone. Bone scans, magnetic resonance imaging, computerized tomography (CAT) scanning, and specialized types of blood tests may be required to accurately diagnose a condition.
Gout and joint infections are considered types of arthritis, but rheumatoid arthritis and osteoarthritis are the types most familiar to most people. Twice as many people are affected by rheumatoid arthritis as are affected by gout, and osteoarthritis affects about five times as many people as are affected by those two combined (see figure). Osteoarthritis is the type of arthritis that most often affects knees. Characterized by the gradual wearing away of cartilage, knee osteoarthritis usually results from the wear and tear of bearing a load over time. Other parts of the knee, including ligaments, muscles, and tendons, may also be affected. Coping remains an important element in managing life after diagnosis with the disease.
Osteoarthritis is the most common type of arthritis, and it is the type that most commonly affects knees. Rheumatoid arthritis and pseudogout (an arthritic condition that mimics gout and is more often found in the knees than gout) also affect the knee joint. These are estimates for common forms of arthritis. (Reprinted from C. J. Strange, "Coping with Arthritis in Its Many Forms," a revised version of an article published in FDA Consumer  and retrieved from http://www.fda.gov/fdac/graphics/1996graphics/arthritis.jpeg).
Research shows that outcome from arthritis depends at least as much on the patient′s own actions as on treatments. Physicians who understand how patients feel about their arthritis are probably more likely to be able to help them. Weiner and Goss in The Complete Book of Homeopathy (Avery Publishing Group, 1989) suggest that too often the approach is to suppress the symptoms with drugs without identifying the underlying causes, thereby allowing the disease itself to progress. People with arthritis have difficulty with daily activities, and emotional problems can cause or exacerbate arthritis. People who have better coping abilities do better with arthritis. Mike and Nancy Samuels, in their book Arthritis: How to Work with Your Doctor and Take Charge of Your Health, describe Aaron Antonovsky′s theory about patients′ ability to cope with illness. Antonovsky argues that seeing problems that arise as opportunities and not threats is part of a health-promoting world view. Part of seeing the world this way is believing that the world is comprehensible, believing that one can cope or manage life and its changes whether alone or with help, and believing that life has meaning and is worth emotional investment. People who have these beliefs cope better with arthritis–and with other challenges of life. Arthritis also tends to be better tolerated by people who have more than twelve years of education. Arthritis is compounded in patients who have experienced long-term tension and anger in their lives.