According to the Center for Disease Control (CDC), arthritis is a term that can describe more than 100 conditions that affect the joints, tissues around the joint, and other connective tissues¹.
This article will explain the key differences between the two most prevalent forms of arthritis, osteoarthritis (OA) and rheumatoid arthritis (RA).
Though both conditions cause joint pain, swelling, difficulty with movement, and joint damage, osteo and rheumatoid arthritis have different root causes and require different approaches for diagnosis and treatment.
OA occurs from mechanical wear and tear on the joints. In contrast, RA is an autoimmune disease that occurs when your immune system malfunctions and attacks your body.
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Osteoarthritis is by far the most common type of arthritis. It currently affects over 32 million Americans². RA affects approximately 1% of the adult population worldwide, including about 1.3 million adults in the US³. While RA can start at any time in your life, OA usually begins later in life. The University of North Carolina’s Osteoarthritis Action Alliance reports that 62% of individuals with OA are women². RA is also three times more common in women⁴ than men.
Arthritis typically damages cartilage (your connective tissues). However, the causes of the damage are different depending on the type of arthritis:
RA is an autoimmune disease in which your immune system will mistakenly attack healthy tissues in the joints. During this process, damaging enzymes destroy the linings of the joints, and the cartilage is released. This results in a lot of pain, swelling, and stiffness.
In OA, protective cartilage wears down gradually, causing bones to rub together. This wear and tear can be attributed to several factors:
Repetitive physical work
Bone spurs grow on the joints and make them stiff and painful
Sports that exert too much pressure on the joints/have repetitive aspects
Although both RA and OA share some of the same symptoms — including joint pain, stiffness in joints, and restricted mobility — there are some important differences outlined below:
Currently, there isn’t a permanent cure for either RA or OA. However, several treatments can help manage symptoms, slow down arthritis progression, and generally improve your quality of life. Your doctor’s recommendations and approach to treatment options will depend on your current health condition.
To treat OA, doctors may recommend using nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce inflammation, alleviate pain, reduce stiffness and improve your range of motion. Other treatment options for OA include corticosteroid injections and surgery.
The American College of Rheumatology⁵ suggests a combination of biologic disease-modifying anti-rheumatic drugs (DMARDs), NSAIDs, or steroidal injections. DMARDs help suppress the immune system⁶ and reduce the damage to the tissues in the joints. Surgery isn’t a typical intervention for RA.
Additional therapies or lifestyle changes
Doctors may also recommend physical therapy and adopting healthy lifestyle changes, such as maintaining a healthy weight to prevent putting excess pressure on your joints. Quitting smoking and avoiding alcohol are also strongly recommended for anyone living with OA or RA.
Diagnosing and distinguishing between OA and RA can be challenging at first due to their overlapping symptoms (especially in the early stages). An arthritis diagnosis starts with a physical exam. In addition, there’s a blood test for RA that can identify two biomarkers (indicators) called cyclic citrullinated peptide antibody and rheumatoid factor.
Your doctor will also measure your levels of C-reactive protein. CRP levels are usually higher in people with inflammatory conditions like RA⁷.
In addition, your physician may order a series of X-rays, MRI scans, and ultrasound scans to confirm the diagnosis and determine the location and extent of your arthritis. In X-rays, the joints in RA look different than joints in OA. With OA, imaging will show less space between the bones and more erosion in RA.
Here are some of the most frequently asked questions people have about RA and OA:
Can you have both RA and OA?
Yes, someone can develop both RA and OA. While OA usually develops after several years of wear and tear on your cartilage, RA tends to develop earlier in life. In addition, people with RA may develop OA with age. If you are 65 years or older and living with OA, you can also develop a condition called elderly-onset rheumatoid arthritis (EORA). EORA tends to affect the larger joints more frequently and has an acute onset.
How do you know if you have OA or RA?
Both OA and RA have similar symptoms, so the most accurate way to determine whether you have OA or RA (or both) is to get a thorough assessment by a medical professional.
Which is more painful, OA or RA?
Arthritis pain typically varies in intensity and duration depending on the type. However, both people with OA or RA may experience severe pain and difficulty moving affected joints.
A person with OA may have morning stiffness in the joints and pain that diminishes after 30 minutes, whereas these symptoms can last hours, days, or even weeks for someone with RA.
Symptoms of RA are often more severe than those of OA, with the most common symptoms being pain and swelling in the hands, wrists, elbows, knees, feet, jaw, and neck. In addition, unlike OA, RA can cause other unpleasant symptoms such as fever, fatigue, and muscle aches.
There are many different types of arthritis affecting millions of people worldwide. However, osteoarthritis and rheumatoid arthritis are two of the most common types of arthritis today. Both OA and RA share several similar symptoms but have different causes and treatments. Therefore, it’s important to distinguish between them and get a professional assessment. Both RA and OA are chronic conditions that can worsen over time if not managed.
Arthritis types | Centers for Disease Control and Prevention
OA prevalence and burden | Osteoarthritis Action Alliance
Arthritis by the numbers | Arthritis Foundation