Osteoarthritis and Rheumatoid Arthritis: What’s the Difference?

Osteoarthritis Versus Rheumatoid Arthritis

Osteoarthritis (OA) is sometimes called degenerative arthritis or degenerative joint disease. It affects around 27 million Americans, this according to the Arthritis Foundation.

Rheumatoid arthritis (RA) is an autoimmune disease where the body’s immune system attacks its own healthy tissues, including the joints, because it thinks these tissues are diseased. According to the American College of Rheumatology, RA affects around 1.3 million Americans.

Even though both these types of arthritis affect the joints, they are entirely different conditions, with additional symptoms for RA and different diagnoses, prognoses and treatments for both. So, what are the differences between osteoarthritis vs rheumatoid arthritis?

The Different Types of Arthritis

According to the Arthritis Foundation, there are over 100 types of arthritis. Yes, you read that right — 100 types! How can we even make a diagnosis if there are that many types of arthritis?

Well, there are five types of arthritis that we see most frequently:

1. Osteoarthritis (OA)
2. Rheumatoid arthritis (RA)
3. Psoriatic arthritis (PsA)
4. Fibromyalgia
5. Gout

What Is Osteoarthritis?

According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, OA is a joint disease that affects the cartilage.

When cartilage is healthy, it allows the joints to move over each other seamlessly. When someone has OA, the cartilage wears down, causing the bones to rub together. This rubbing causes pain, swelling, and an overall decrease in function and movement of the affected joint.

OA typically is a slow process and happens over a long period of time. Certain things can predispose a person to OA and can “speed up the process" of wearing down the cartilage:

• Being overweight or obese, as it puts extra weight on the joints
• The aging process
• An acute injury to the joint
• Malformations of the joints
• Genetic defects in joint cartilage
• Stress to the joints; this can happen from specific jobs or sports

What Is Rheumatoid Arthritis?

RA is an arthritic condition that is more than just arthritis — it is an autoimmune disease that is caused by the body mistakenly attacking its own tissues.

Whereas OA affects the cartilage of the joints, RA affects the internal lining of the joints. This causes swelling of the joints that causes bone loss and deformities of the affected joints.

While OA is typically an "overuse" condition, RA affects any joint in the body. However, it tends to affect the small joints first, such as the joints in the hands and the feet. As the disease progresses, it will affect the larger joints, such as the knees, elbows, and hips.

Forty percent of RA sufferers have symptoms that are not even associated with joint pain, symptoms that can affect the eyes, lungs, heart, and kidneys, for example.

Prevalence of OA and RA

• OA is the most common type of arthritis in the United States. It is also the leading cause of disability in older adults.
• The most common type of OA is knee OA, affecting 10% of men and 13% of women, this according to a report in Clinics in Geriatric Medicine.   The number of people with OA is increasing due to aging and obesity.
• RA affects about 1% of the world’s population, this according to a 2017 report from Cornell University. It affects twice as many women as it does men.
• RA also affects children. It can develop at any age, but the average age of diagnosis is between ages 30 and 60.

What Are the Symptoms of OA and RA?

OA symptoms develop slowly over a period of many years. They tend to worsen over time. RA symptoms start suddenly, and the condition can quickly worsen within a few weeks.

Symptoms of OA

OA symptoms vary depending on the which joints are affected and how severely they are affected. The most common symptoms, however, are pain and stiffness, especially after waking in the morning and after sitting for extended periods.

OA affected joints may get swollen after activity and build up over time.

Additional symptoms of OA are:

• Sore/stiff joints, especially the hips, knees and low back, after inactivity
• Limited range of motion and stiffness that goes away after moving around
• Clicking or cracking sounds when the joints move
• Swelling around affected joints
• Pain after activity or after a long day

The joints most often affected by OA are the hips, knees, fingers, and feet. And OA pain, swelling, and stiffness makes it harder to perform everyday tasks.

Symptoms of RA

Early on, people with RA may not notice redness and swelling in the joints. They may, however, experience pain.

Additional joint symptoms indicative of RA are:

• Joint pain, swelling, and tenderness that has lasted more than six weeks
• Morning stiffness lasting more than a half hour
• Inflammation affecting more than one joint
• Inflammation affecting the small joints of the wrists, hands and/or feet
• Same joints on both sides are affected

People with RA also experience fatigue, low-grade fevers, and problems with appetite.

People with RA experience flares, periods where the disease is more active, and these flare periods can last from days to weeks.

Ongoing inflammation throughout the body can cause problems.

Here are some ways RA can affect the rest of the body:

• Eyes – causing pain, redness, and dryness, sensitivity to light and vision issues
• Mouth – dryness and gum problems, including infection
• Skin – dry, itchy, and inflamed skin and rheumatoid nodules - small bumps under the skin over bony areas
• Lungs – inflammation may cause scarring and breathing problems
• Blood vessels – blood vessel inflammation can cause damage to nerves, skin and other organs
• Blood – Anemia causes lower red blood cells than normal

Treatment of Osteoarthritis vs Rheumatoid Arthritis

Both types of arthritis can cause significant pain that can be life-altering. Treatment typically involves treating the symptoms, often with the use of pain medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs). Keeping mobile is also important, so exercise may also be recommended, perhaps in the form of walking or yoga.

RA treatment, however, is much more expansive. Because it is an autoimmune disease, it often requires more medications to treat it.

Steroids may be prescribed to reduce inflammation. Medications may be used to slow the progression of the disease; these medicines are called disease-modifying antirheumatic drugs (DMARDs.) Examples include methotrexate (Trexall, Otrexup, and Rasuvo) and hydroxychloroquine (Plaquenil.)

A newer class of DMARDs called biologic response modifiers are also often prescribed, typically in conjunction with methotrexate. These medications help to reduce inflammation by targeting the part of the immune system that causes the inflammation. Examples include adalimumab (Humira) and rituximab (Rituxan.)

Outlook

Both RA and OA are chronic diseases, meaning you will have them for the rest of your life.

OA is degenerative, so it will continue to worsen with time. With treatment and lifestyle changes, OA generally has a positive outlook.

The outlook for RA cannot be predicted. It is a disease where numerous complications are possible.

The good news is newer treatment options are leading to more positive outcomes than they did in the past. Many RA patients can maintain a good quality of life and continue to work and enjoy physical and social activities.

Some people with RA have a more progressive form of RA, which causes persistent inflammation and can lead to joint damage and other disease complications.

You can improve your outlook for either OA and RA by practicing healthy habits and keeping up with your treatments. When your arthritis symptoms are managed, your quality of life is improved and your emotional and mental health fares better.