Osteoarthritis (OA)

Reviewed/Revised Sept 2024
VIEW PROFESSIONAL VERSION
Get the full details

Arthritis is a group of diseases that makes your joints hurt, swell up, and turn red. There are many different types of arthritis.

What is osteoarthritis?

Osteoarthritis is the most common type of arthritis. In osteoarthritis, the cartilage in your joints wears away.

  • Osteoarthritis often begins in people between 40 and 50 years old and affects almost everyone by age 80

  • You may have joint pain, swelling, and stiffness (especially in the morning)

  • Being overweight and having a job that uses the same joints over and over increase your risk of getting osteoarthritis fairly young

  • Doctors look at your symptoms and take x-rays to tell if you have osteoarthritis

  • Doctors treat osteoarthritis with exercises, medicines, and sometimes surgery

What causes osteoarthritis?

Osteoarthritis is usually caused by stress on a joint. The stress wears away the cartilage in the joint. Cartilage is a smooth, tough, protective layer of tissue on the ends of bones in each joint. The cartilage cushions the bones and lets them slide over each other without friction:

  • When the cartilage is damaged, bones in the joint start to rub against each other and become damaged

  • With damage to the cartilage and bone, the joint can no longer move smoothly and work correctly

You have a higher risk of getting osteoarthritis if you:

  • Are an older woman

  • Are overweight

  • Have already injured a joint

  • Have weak muscles or damaged nerves in your legs or arms

  • Do work that puts stress on your joints

  • Have family members with osteoarthritis

What are the symptoms of osteoarthritis?

Common symptoms are:

  • Pain or a deep ache that's worse when you put weight on the joint (such as when standing)

  • Stiffness in your joints after sleeping or staying still that goes away about 30 minutes after moving around

  • Joints that don't straighten or bend fully

  • Joints that grind, grate, or crackle when you move

  • Swollen finger joints

  • Loose, unstable joints

Osteoarthritis usually starts in one or a few joints. It gets worse slowly after symptoms start. Many people with osteoarthritis may not be able to do everything they used to do.

How can doctors tell if I have osteoarthritis?

Doctors can tell if you have osteoarthritis based on your symptoms and by doing an exam. Doctors may also do:

  • X-rays

  • Blood tests to rule out other diseases

  • Tests to look at joint fluid, if the joint is swollen

How do doctors treat osteoarthritis?

The main goals of treatment are to:

  • Relieve your pain

  • Keep your joints flexible

  • Keep your joints working and you moving

Medicines, together with exercise and therapy, can help with symptoms.

Medicines

Doctors may recommend over-the-counter pain relievers, such as:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs) by mouth

  • NSAID creams that can be rubbed on the skin

Doctors may also prescribe stronger medicines for pain or inject medicines, such as corticosteroids, into a painful, swollen joint.

Exercises

  • Daily stretching exercises (such as yoga)

  • Strengthening exercises (such as weight lifting)

  • Low-impact aerobic exercises (such as walking, swimming, or bicycle riding)

  • Water exercises to avoid stressing the joint

Other treatments

  • Physical therapy

  • Occupational therapy (to help you do daily activities)

  • Supports (such as straight back chairs, shoe inserts, or canes)

  • Cold compresses or heating pads

  • Massage

  • Avoiding overly soft beds and seats

When other treatments don't work, doctors may suggest surgery to replace a badly damaged joint with an artificial one.

Drugs Mentioned In This Article

quizzes_lightbulb_red
Test your KnowledgeTake a Quiz!
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID