What is arthritis?
Arthritis is a general term for a group of more than 100 diseases. The word "arthritis" means "joint inflammation." Arthritis is inflammation in and around the body's joints. A joint is a point at which two or more bones come together, such as the hip or the knee. Inflammation is one of the body's natural reactions to disease or injury. Pain, stiffness, and swelling can result from inflammation.

Arthritis can cause loss of movement in some patients. The disorder limits everyday activities such as walking, dressing, and bathing for more than 7 million Americans. Arthritis is the leading cause of disability among Americans aged 15 and older. However, arthritis affects people in all age groups, including almost 300,000 children. Some types of arthritis include osteoarthritis, rheumatoid arthritis, and gout.

What are the symptoms of arthritis?
Different types of arthritis have different symptoms, which can range in severity from person to person. Osteoarthritis generally does not cause any symptoms outside the joint. Symptoms of other types of arthritis might include fatigue, fever, a rash, and the signs of joint inflammation, including:

• Pain
• Swelling
• Stiffness
• Tenderness
• Redness
• Warmth

What causes arthritis?
The causes of most types of arthritis are unknown. Scientists currently are studying what roles three major factors play in certain types of arthritis. The three areas being studied are:

• Genetic factors
• What happened during a person's lifetime
• The person's current lifestyle

Although the exact cause of arthritis might not be known, there are several risk factors for arthritis. A risk factor is a trait or behavior that increases a person's chance of developing a disease or predisposes a person to a certain condition. Risk factors for arthritis include:

• Age — The risk of developing arthritis, especially osteoarthritis, increases with age.
• Gender — In general, arthritis occurs more frequently in women than in men.
• Weight — Being overweight puts extra stress on weight-bearing joints, increasing wear and tear, and the risk of arthritis.
• Work factors — Some jobs that require repetitive movements or heavy lifting can cause stress in the joints and/or cause an injury, which can lead to arthritis.

The pain of arthritis might come from different sources. These might include inflammation of the synovial membrane(tissue that lines the joints), tendons, or ligaments; muscle strain; and fatigue. A combination of these factors contributes to the intensity of the pain. The pain of arthritis varies greatly from person to person. Variables that contribute to the pain include swelling within the joint and damage that has occurred within the joint.

How is arthritis diagnosed?
In diagnosing arthritis pain, a doctor usually will take a medical history and ask questions about the patient's pain. The doctor will do a physical examination to determine causes of pain and how this pain is affecting the patient's ability to function. The patient might undergo X-rays or other imaging procedures such as a CT scan (computerized tomography) or MRI (magnetic resonance imaging) to see how much joint damage has been done.

How is arthritis treated?
Treatment of arthritis will depend on the type of arthritis, its severity, and the arthritis patient's overall health. A number of different specialists might be involved in the care of a patient with arthritis. The goal is to treat all aspects of arthritis pain, increase joint mobility and strength, and help patients learn to manage pain. Treatment options include medicine, exercise, heat/cold, use of joint protection, and surgery. Individual treatment plans might involve more than one of these options.

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