Differences Between Osteoarthritis And Rheumatoid Arthritis

Arthritis is the medical term for inflammation of the joint. It is felt as pain, seen as swelling and often there is heat and redness of the skin over the joint. The term arthritis should not be confused with “arthralgia” which means joint pain. There are several different types of arthritis that are classified primarily by the nature of the joint disease or the cause. The two most common types are osteoarthritis (OA) and rheumatoid arthritis (RA), which differ significantly in the nature of the disease process. Often these two types of arthritis are confused with each other. There may be some common symptoms like joint pain but it is important to know that osteoarthritis and rheumatoid arthritis are not the same type of joint problem.

Age and Gender

Osteoarthritis (OA) affects more than half of all people over the age of 60 years. It is often seen as an inevitable consequence of aging. In fact, by the time you are 70, you will almost definitely have osteoarthritis irrespective of whether you are male or female. But in the early senior years, men are usually more affected by osteoarthritis than women. Rheumatoid arthritis (RA) is a joint disease largely due to a dysfunction of the immune system. It tends to start earlier in life, around the 20s and 30s, and is more frequently seen in women.

Part of the Joint

In osteoarthritis, it is the cartilage that caps the ends of the bones that are affected. This articular cartilage normally protects the ends of the bones from rubbing against each other. Eventually it wears down and the ends of the bones start rubbing together. In rheumatoid arthritis (RA), it is the lining around the joint that is affected. This synovial lining is a thin membrane that produces synovial fluid or joint fluid. Normally this joint fluid reduces friction in the joint during movement.

Joint Disease

Osteoarthritis is a degenerative condition. This means that the cartilage of the joint is gradually eroded. Normally the cartilage is able to stand wear and tear by constantly repairing itself. But as you get older or put too much of strain on the joint, the cartilage cannot heal itself quickly enough. Eventually the cartilage is worn down, breaks into pieces and exposes the underlying bone. With rheumatoid arthritis, the synovial lining becomes inflamed. It is believed that the inflammation is due to the body’s immune system attack the lining for some reason. Therefore rheumatoid arthritis is known as an autoimmune condition.

Location Affected

Both osteroarthritis and rheumatoid arthritis can affect any joint in the body. Osteoarthritis tends to affect the large joints like the knee and shoulder, while rheumatoid arthritis tends to affect the small joints like the finger joints. There are different types of joints in the body classified according to its structure and the way it moves. Both osteoarthritis and rheumatoid arthritis tend to affect synovial joints. Another characteristic feature of rheumatoid arthritis is that it the joints on both side of the body are usually affected to the same degree.

Arthritis Symptoms

The symptoms of both osteoarthritis and rheumatoid arthritis are largely the same. These common symptoms include pain, joint stiffness, swelling and heat of the skin over the joint. But there are a few subtle differences. In osteoarthritis, the stiffness tends to be the main symptom leading to a reduced range of motion. While movement can ease the stiffness, it eventually worsens the pain and stiffness especially if a person is very active.

In rheumatoid arthritis, the joint stiffness is worse upon waking in the morning or after long periods of inactivity. Moving around eases the stiffness. Pain is also quite prominent in rheumautoid arthritis along with tenderness, swelling, heat and redness of the skin. As osteoarthritis and rheumatoid arthritis progresses, nodules and lumps in the joint may form. Nodule formation is seen with rheumatoid arthritis while bony lumps may develop in osteoarthritis.