Arthritis is a joint disorder featuring inflammation. A joint is an area of the body where two different bones meet. A joint functions to move the body parts connected by its bones. Arthritis literally means inflammation of one or more joints.

There are many forms of arthritis (over one hundred and growing). The forms range from those related to wear and tear of cartilage (such as osteoarthritis) to those associated with inflammation resulting from an over-active immune system (such as rheumatoid arthritis).

The causes of arthritis depend on the form of arthritis. Causes include injury (leading to osteoarthritis), abnormal metabolism (such as gout and pseudogout), inheritance, infections, and for unclear reasons (such as rheumatoid arthritis and systemic lupus erythematosus).

Arthritis is classified as one of the rheumatic diseases. These are conditions that are different individual illnesses, with differing features, treatments, complications, and prognosis. They are similar in that they have a tendency to affect the joints, muscles, ligaments, cartilage, tendons, and many have the potential to affect internal body areas.

Symptoms of arthritis include pain and limited function of joints. Inflammation of the joints from arthritis is characterized by joint stiffness, swelling, redness, and warm. Tenderness of the inflamed joint can be present.

Many of the forms of arthritis, because they are rheumatic diseases, can involve symptoms affecting various organs of the body that do not directly involve the joints. Therefore, symptoms in some patients with arthritis can also include nonspecific fever, weight loss, fatigue, and feeling unwell.

The first step in the diagnosis of arthritis is a meeting between the doctor and the patient. The doctor will review the history of symptoms, examine the joints for inflammation and deformity, as well as ask questions about or examine other parts of the body for inflammation or signs of diseases that can affect other body areas. Furthermore, certain blood, urine, joint fluid and/or x-ray tests might be ordered. The diagnosis will be based on the pattern of symptoms, the distribution of the inflamed joints, and any blood and x-ray findings. Several visits may be necessary before the doctor can be certain of the diagnosis.

Many forms of arthritis are more of an annoyance than serious. However, millions of patients suffer daily with pain and disability from arthritis or its complications.

Earlier and accurate diagnosis can help to prevent irreversible damage and disability. Properly guided programs of exercise and rest, medications, physical therapy, and surgery options can idealize long-term outcomes for arthritis patients.