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Arthritis

What is arthritis?

Arthritis is a disease that affects your joints (areas where your bones meet and move). Arthritis usually involves inflammation or degeneration (breakdown) of your joints. These changes can cause pain when you use the joint.

Arthritis is most common in the following areas of the body:

  • Feet.
  • Hands.
  • Hips.
  • Knees.
  • Lower back.

What are the parts of a joint?

Joints get cushioned and supported by soft tissues that prevent your bones from rubbing against each other. A connective tissue called articular cartilage plays a key role. It helps your joints move smoothly without friction or pain.

Some joints have a synovial membrane, a padded pocket of fluid that lubricates the joints. Many joints, such as your knees, get supported by tendons and ligaments. Tendons connect muscles to your bones, while ligaments connect bones to other bones.

What are the different types of arthritis?

Arthritis is a broad term that describes more than 100 different joint conditions. The most common types of arthritis include:

  • Osteoarthritis, or “wear and tear” arthritis, which develops when joint cartilage breaks down from repeated stress. It’s the most common form of arthritis.
  • Ankylosing spondylitis, or arthritis of the spine (usually your lower back).
  • Juvenile arthritis (JA), a disorder where the immune system attacks the tissue around joints. JA typically affects children 16 or younger.
  • Gout, a disease that causes hard crystals of uric acid to form in your joints.
  • Psoriatic arthritis, joint inflammation that develops in people with psoriasis (autoimmune disorder that causes skin irritation).
  • Rheumatoid arthritis, a disease that causes the immune system to attack synovial membranes in your joints.

How common is arthritis?

Arthritis is the most common cause of disability in the U.S. About 50 million adults and 300,000 children manage some form of arthritis.

SYMPTOMS AND CAUSES

What causes arthritis?

Different types of arthritis have different causes. For instance, gout is the result of too much uric acid in your body. But for other types of arthritis, the exact cause is unknown. You may develop arthritis if you:

  • Have a family history of arthritis.
  • Have a job or play a sport that puts repeated stress on your joints.
  • Have certain autoimmune diseases or viral infections.

What are the risk factors for arthritis?

Some factors make you more likely to develop arthritis, including:

  • Age: The risk of arthritis increases as you get older.
  • Lifestyle: Smoking or a lack of exercise can increase your risk of arthritis.
  • Sex: Most types of arthritis are more common in women.
  • Weight: Obesity puts extra strain on your joints, which can lead to arthritis.

What are the symptoms of arthritis?

Different types of arthritis have different symptoms. They can be mild in some people and severe in others. Joint discomfort might come and go, or it could stay constant. Common symptoms include:

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

DIAGNOSIS AND TESTS

How is arthritis diagnosed?

If you think you may have arthritis, see your healthcare provider. The provider will ask about your symptoms and learn how joint pain affects your life. Your provider will perform a physical exam, which may include:

  • Assessing mobility and range of motion in your joints.
  • Checking for areas of tenderness or swelling around your joints.
  • Evaluating your overall health to determine if a different condition could be causing your symptoms.

Can imaging exams detect arthritis?

Imaging exams can help your healthcare provider get a clear picture of your bones, joints and soft tissues. An X-ray, MRI or ultrasound can reveal:

  • Bone fractures or dislocations that may be causing you joint pain.
  • Cartilage breakdown around your joints.
  • Muscle, ligament or tendon injuries near your joints.
  • Soft tissue inflammation.

Can a blood test detect arthritis?

There is no blood test that can directly detect arthritis. But if your healthcare provider suspects gout or rheumatoid arthritis, they may order blood work. It looks for uric acid or inflammatory proteins.