The Difference Between Osteoarthritis and Rheumatoid Arthritis

There are more than 100 varieties of arthritis. The term arthritis literally means “inflammation (swelling) of a joint.”

Osteoarthritis (OA) and Rheumatoid Arthritis (RA) are two of the most common types of arthritis, with OA being more common than RA. Both OA and RA are characterized by inflammation in the joints, with RA having more intense levels of inflammation.

OA and RA Facts

OA affects more than 30 million individuals in the United States alone and is the most common joint disease worldwide.  On the basis of X-rays, there are estimates that 80 to 90 percent of adults over the age of 65 have some degree of OA. As a result, it is the leading cause of chronic disability in older adults, costing greater than $185 billion annually.

In contrast, RA affects just over 1.3 million Americans and approximately one percent of the world’s population. RA is much more common in women. In fact, they are up to three times more likely to develop RA than men. In women, it generally starts between the ages of 30 and 60. RA is also a significant cause of disability. Plus, 60 percent of people with inadequately treated RA are unable to work 10 years after the start of symptoms.

Characteristics of OA and RA

Characteristic OA RA
CauseDegenerative (i.e., “wear and tear” causing breakdown of cartilage cushion in joint)Autoimmune (i.e., your body attacks itself; in this case, your own joints)
Joint symptoms

Pattern of involvement

Morning stiffness
Painful, swollen, and stiff joints with Heberden’s nodes and Bouchard’s nodes

Asymmetrical (i.e., on only one side of the body)

Usually lasts less than one hour
Painful, swollen, and stiff joints with rheumatoid nodules

Symmetrical (i.e., on both sides of the body)

Usually lasts longer than one hour

Not typically associated with the diseaseVery commonly associated with the disease and can affect organs such as the heart, lungs, eyes, and kidneys as well as have fevers, fatigue, and weight loss
Risk factors
  • Older age (risk increases with age)

  • Obesity (body mass index [BMI] > 30 kg/m2)

  •  Joint injuries

  • Repeated stress on a joint (usually occupational)

  • Genetics (some people inherit forms of OA)

  • Metabolic diseases such as diabetes, gout (excess uric acid), and hemochromatosis (excess iron)
  • Sex (women three times more likely than men)

  • Genetics (significant family history of disease)

  • Smoking

  • Environment exposures such as asbestos and silica

Blood tests

Imaging tests

  • There is no blood test that diagnoses OA, but they can be used to rule out other causes of joint symptoms such as RA

  • X-rays (can reveal joint space narrowing and/or bone spurs)

  • Magnetic resonance imaging (MRI; may be needed for more information in complex cases)

  • Erythrocyte sedimentation rate (ESR or “sed rate”; a marker of inflammation)

  • C-reactive protein (CRP; another marker of inflammation)

  • Rheumatoid factor (RF)

  • Anti-cyclic citrullinated peptide (anti-CCP) antibodies

  • X-rays, MRI, and ultrasound can be used to track progression/severity of the disease





  • Acetaminophen (Tylenol)

  • Nonsteroidal anti-inflammatory drugs (NSAIDs; over the counter such as ibuprofen [Advil] or naproxen [Aleve] or by prescription)

  • Duloxetine (Cymbalta), which is helpful for OA with chronic pain

  • Physical therapy

  • Occupational therapy

  • Steroid injections

  • Hyaluronic acid injections (a material that is similar to human joint fluid)

  • Total joint replacement (arthroplasty)

  • NSAIDs

  • Steroids

  • Disease-modifying antirheumatic drugs (DMARDs; common ones include methotrexate, leflunomaide [Arava], hydroxychloroquine [Plaquenil], and sulfasalazine [Azulfidine])

  • Biologic agents (common ones include abatacept [Orencia], adalimumab [Humira], etanercept [Enbrel], and tofacitinib [Xeljanz])

  • Physical therapy

  • Occupational therapy

  • Synovectomy (removal of the inflamed lining of a joint)

  • Joint fusion

  • Total joint replacement (arthroplasty)

Related Articles: Everything You Need to Know About Rheumatoid ArthritisRheumatoid Arthritis: Natural Treatments and Diet, and 10 Best Exercises for Rheumatoid Arthritis Recommended by Doctors

Jul 2, 2019