Robert S Pinals, MD
RN Maini, BA, MB BChir, FRCP, FMedSci, FRS
Paul L Romain, MD
ARTHRITIS OVERVIEW — Arthritis refers to inflammation of the joints. The inflammation can affect any of the important structures inside a joint, including the joint lining (synovium), bones, cartilage, or supporting tissues. Common symptoms of arthritis include pain, stiffness, and swelling of the joint. The condition may affect only one or several joints throughout the body.
There are many possible causes of arthritis, although some are much more common than others. Some types of arthritis respond well to treatment and resolve without any lingering effects, whereas other types of arthritis are more difficult to control and can be disabling.
This topic provides an overview of arthritis; more detailed information about the various types of arthritis is also available.
ARTHRITIS CAUSES — There are many possible causes of arthritis, including age-related wear and tear, infections, autoimmune conditions, injuries, and others. Topic reviews that discuss specific types of arthritis are available separately (see ‘Where to get more information’ below).
Joint symptoms — The most common symptoms of arthritis include joint pain and stiffness. There may also be joint tenderness, swelling, and limited movement of one or more joints. The skin over the joint is sometimes red.
There are two main types of arthritis: inflammatory arthritis, which is caused by rheumatic conditions or infection, and non-inflammatory arthritis, which is caused by injury, aging, or other causes. The location, timing, and pattern of joint pain and swelling can help to distinguish between inflammatory and non-inflammatory arthritis.
Inflammatory arthritis — usually causes stiffness with rest, especially morning stiffness. It often affects joints on both sides of the body.
Noninflammatory arthritis — usually causes pain that is aggravated by movement and weight bearing and is relieved by rest. Joints on one or both sides of the body may be affected.
ARTHRITIS DIAGNOSIS — The process of diagnosing arthritis involves several steps. A medical history and physical examination usually provide the most helpful information; laboratory tests, x-rays, and other tests are sometimes needed.
Laboratory tests — Laboratory tests are sometimes, but not always, needed to determine the cause of arthritis. Blood tests may be recommended if the arthritis does not improve with watchful waiting and conservative treatment.
Testing of the fluid inside a joint, called the synovial fluid, is often helpful in determining the cause of a person’s arthritis. The fluid is removed by inserting a needle inside the joint and withdrawing a sample of fluid. This procedure is called a “joint tap”; pain or stiffness that is caused by an accumulation of fluid in the joint is often relieved after fluid is removed.
X-rays and other imaging tests — X-rays provide detailed pictures of bones. Other imaging tests, such as ultrasound, magnetic resonance imaging (MRI), and computer aided tomography (CT scan) provide images of the tissues inside and surrounding the joints. One or more of these imaging tests may be recommended to diagnose fractures, calcium deposits, or changes in the shape of a joint.
X-rays are often not usually helpful early in the course of arthritis. For many types of arthritis, changes in the joint are not visible on x-ray for months or even years. However, x-rays are often useful for monitoring over time.
WHEN TO SEEK HELP — Some signs and symptoms of arthritis require urgent medical care. If you have one or more swollen joints and any of the following, you should seek medical care as soon as possible.
- Weight loss
- An overall feeling of being unwell
- Sudden weakness of specific muscle groups or
- Burning pain, numbness, or a pins-and-needles sensation
ARTHRITIS TREATMENT — The treatment of arthritis depends upon the specific cause. (See “Patient information: Osteoarthritis treatment” and “Patient information: Rheumatoid arthritis treatment”.)
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed every four months on our web site (www.uptodate.com/patients).
Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient Level Information:
Patient information: Osteoarthritis symptoms and diagnosis
Patient information: Rheumatoid arthritis symptoms and diagnosis
Patient information: Gout
Patient information: Pseudogout
Patient information: Systemic lupus erythematosus (SLE)
Patient information: Ankylosing spondylitis and spondyloarthritis
Patient information: Psoriatic arthritis
Patient information: Reactive arthritis (formerly Reiter syndrome)
Patient information: Osteoarthritis treatment
Patient information: Rheumatoid arthritis treatment
Patient information: Joint infection
Professional Level Information:
Arthritis associated with gastrointestinal disease
Clinical features of rheumatoid arthritis
Clinical manifestations and diagnosis of psoriatic arthritis
Diagnosis and differential diagnosis of rheumatoid arthritis
Diagnostic imaging of joint pain
Evaluation of the adult with monoarticular pain
Evaluation of the adult with polyarticular pain
General principles of management of rheumatoid arthritis
Overview of the systemic and nonarticular manifestations of rheumatoid arthritis
Septic arthritis in adults
Specific viruses that cause arthritis
Treatment of psoriatic arthritis
Clinical manifestations, diagnosis, and management of undifferentiated spondyloarthritis and related spondyloarthritides
The following organizations also provide reliable health information.
- National Library of Medicine
(www.nlm.nih.gov/medlineplus/arthritis.html, available in Spanish)
- National Institute of Arthritis and Musculoskeletal and Skin Diseases
- National Institute on Aging
(www.nia.nih.gov/HealthInformation/Publications/arthritis.htm, available in Spanish)
- American College of Rheumatology
- The Arthritis Foundation
Patient Support — There are a number of online forums where patients can find information and support from other people with similar conditions.
- About.com Arthritis Forum