Basic information about osteoarthritis

For information about arthritis management and treatment options, please visit our Living with Arthritis and treatment pages. For information about the cost and prevalence of osteoarthritis, please visit our Policy Solutions section.

Osteoarthritis (AH-stee-oh-ar-THREYE-tis) is the most common type of arthritis and is seen especially among older people.

Osteoarthritis mostly affects cartilage (KAR-til-uj), the hard but slippery tissue that covers the ends of bones where they meet to form a joint. Healthy cartilage allows bones to glide over one another. It also absorbs energy from the shock of physical movement. In osteoarthritis, the surface layer of cartilage breaks and wears away. This allows bones under the cartilage to rub together, causing pain, swelling, and loss of motion of the joint. Over time, the joint may lose its normal shape. Also, small deposits of bone—called osteophytes or bone spurs—may grow on the edges of the joint. Bits of bone or cartilage can break off and float inside the joint space. This causes more pain and damage.

— National Institutes of Health, Publication No. 15-4617

What Causes Osteoarthritis?

  • Being overweight
  • Aging
  • Joint injury
  • Joints that are not properly formed
  • A genetic defect in joint cartilage
  • Stresses on the joints from certain jobs and playing sports.

What are the Symptoms?

  • Joint pain typically in the hands, knees, hips and spine.
  • Stiffness in a joint after getting out of bed or sitting for a long time.
  • Swelling or tenderness in one or more joints.

How Is Osteoarthritis Treated?

Doctors often combine treatments to fit a patient’s needs, lifestyle, and health.

  • Improve joint function through exercise such as walking
  • Keep a healthy body weight
  • Nondrug pain relief techniques to control pain
  • Rest and joint care
  • Complementary and alternative therapies
  • Surgery

You can learn more about symptom management on our Living with OA page.

Learn more from our partner organizations