Difference Between RA and OA

There are numerous types of arthritis (inflammtion within the joints) known to humans but the most common types are Osteoarthritis (OA) and Rheumatoid Arthritis (RA). Being a healthcare practitioner and a son to both parents who suffer from the said diseases, I became more interested in looking for more information with regards to the difference of the two. RA being an autoimmune disorder (it means that your body's cellular defenses attack your own cells) is systemic in nature, which usually affects both pairs of joints. On the other hand, OA is a wear and tear type of arthritis, which means that mechanical forces applied within the joint is a prelude to the inflammtion that occurs afterwards (this signifies that obese and older individuals are more opt to have OA). To better understand their difference, here is a table that summarizes the difference between OA and RA:

Characteristic	Rheumatoid arthritis	Osteoarthritis
Age of onset	Typically 30 to 50 years old, but can appear from age 8 to 80	Usually older than 55; rare before 40
Type of onset	Relatively rapid, over weeks to months	Slow, over years
Location of affected joints	Usually small joints on both sides of the body (symmetric): wrists, knuckles, ankles, toes, and also shoulders, elbows, hips, knees, and the neck	Usually a few joints that may or may not be on both sides (asymmetric), though many joints may be affected, most commonly hips, knees, thumbs, and the fourth and fifth finger joints. Very rarely involves the wrists, ankles, or elbows unless there was preceding injury or stress to the joint.
Symptoms of arthritis	Swelling, prolonged stiffness (hours)	Swelling rarely occurs except in knees. Stiffness may be severe but is brief in duration (less than 30 minutes). Stiffness returns at the end of the day or after periods of activity.
Associated symptoms	Frequent feelings of "being sick inside," with fevers, weight loss, or involvement of other organ systems	Symptoms occur in isolation, with no systemic symptoms.