2. The Cause is Different
Osteoarthritis usually starts later in life because it’s the result of wear and tear on joints, according to WebMD. Meanwhile, rheumatoid arthritis is an autoimmune disease, meaning the body’s own defenses attack joints and cause problems.
To diagnose osteoarthritis, a doctor will collect your medical history and inspect the location of the pain. Meanwhile, rheumatoid arthritis can be more difficult to diagnose in the early stages, as there is “no one blood test or physical finding to confirm the diagnosis,” notes the Mayo Clinic. However, while blood tests usually aren’t helpful to detect osteoarthritis, a patient with rheumatoid arthritis could have specific markers in the blood that point to inflammation in the body, it adds.