There are over 100 types of arthritis and related diseases. Two of the most common types are rheumatoid arthritis (RA) and osteoarthritis (OA). OA is more common than RA.
Both OA and RA involve inflammation in the joints, but the inflammation in RA is much greater. Until recently, healthcare professionals believed that inflammation was not present in OA.
OA and RA share some symptoms. RA can affect multiple joints in a subtype called polyarticular arthritis, and it tends to affect the body symmetrically. OA usually affects a few joints and typically occurs on only one side of the body.
In this article, we take a look at the similarities and differences between RA and OA, including their symptoms, causes, and treatments.
Causes
Joint pain and stiffness are common to both rheumatoid arthritis and osteoarthritis.
Joints contain protective tissues that prevent the bones from scraping against one another. For example, cartilage overlies the bones to allow smooth movement in the joint. Arthritis damages this protective tissue.
The causes of joint damage are different in RA and OA:
Rheumatoid arthritis
RA is an autoimmune disease. It occurs when a person’s immune system mistakenly attacks healthy tissues in the joints.
This immune response involves both genetic and environmental factors, including cigarette smoking.
Osteoarthritis
In OA, the protective cartilage gradually wears down and the bones begin to scrape against one another. This wear and tear can result from repetitive movements, such as in sports, that place pressure on the joints.
Symptoms
RA and OA share a number of symptoms, including:
- joint pain
- stiffness in joints
- swelling, which is more severe in RA
- restricted mobility in affected joints
- symptoms that are worse in the morning
The symptoms of RA may arise and get worse quickly, sometimes within a few weeks. However, the symptoms of OA appear more slowly, as the protective tissues in the joints gradually break down.
However, OA stressors, such as going for a hike, may cause a sudden, severe swelling in the knee.
Both OA and RA can affect any joint in the body. OA is most likely to affect the knees and the small finger and thumb joints. RA often occurs in the hands, fingers, elbows, knees, feet, and hips, and it usually occurs in the same joints on both sides of the body.
The symptoms of RA usually affect the joints on both sides of the body. For example, if RA affects one hand, it also affects the other hand. OA often only affects one side of the body.
OA is localized, as it only affects the joint and its surrounding tissues. For this reason, OA typically only affects one joint, while RA commonly affects multiple joints.
A key difference between these forms of arthritis is that RA involves a range of systemic symptoms, which are symptoms that affect the entire body.
Symptoms that affect people with RA include:
- fatigue
- fever
- loss of appetite
- weight loss
- inflammation in other areas, such as the eyes and lungs
- rheumatoid nodules
OA is not associated with systemic symptoms, but people with the condition can develop bone spurs or other bone abnormalities.
For example, OA in the hands can often cause small lumps to develop around the ends of the finger joints.
Diagnosis
Doctors diagnose RA and OA by performing a physical examination, taking a medical history, and carrying out various diagnostic tests.
Diagnosing these conditions can be challenging. This is because the symptoms often overlap, particularly in the early stages.
Blood tests can help diagnose or rule out RA, as this condition leaves certain biomarkers in the blood, such as cyclic citrullinated peptide antibody and rheumatoid factor.
They may also check for abnormal levels of the C-reactive protein antibody, which is a marker that indicates inflammation.
Doctors may also perform imaging tests, such as X-rays, MRI, and ultrasound scans, to determine the extent and location of the RA or OA damage.
Treatment
For people with RA and OA, ibuprofen and other NSAIDs can reduce inflammation.
RA and OA are chronic conditions.
There is currently no cure for them, but various treatments can help a person manage their symptoms, improve their quality of life, and slow down the progression of the condition.
Treatment may involve using medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce inflammation. Reducing inflammation can help alleviate pain and stiffness in the joints and improve their range of motion.
Doctors may also recommend steroid-based medications to reduce inflammation. For example, they may inject steroids directly into the affected joints when it is important to reduce inflammation immediately.
Healthcare professionals advise taking disease-modifying antirheumatic drugs (DMARDs), often alongside NSAIDs or steroids and biologics, to treat RA. DMARDs aim to suppress the immune system and reduce its damage to tissues in the joints.
Treatments for both RA and OA will often also involve physical therapy. This helps improve a person’s mobility and keep joints flexible.
Following a healthful anti-inflammatory diet can also help. Maintaining a healthy weight can help prevent the need to place excess pressure on the joints. Avoid smoking cigarettes, particularly in RA.
Outlook
RA and OA are chronic conditions that cause pain and stiffness in the joints. Both conditions can become worse over time without appropriate treatment. The effects of OA and RA on a person’s daily life range from mild to severe.
RA and OA can cause similar symptoms, but they have different causes and treatments. In many cases, OA is easier to treat than RA because it usually affects fewer joints and does not involve systemic symptoms. The progression of RA is more difficult to predict than that of OA.
With modern research and treatments, the outlook for people with RA has greatly improved. Doctors can usually prevent or slow down the progression of this disease with effective treatment.
