Arthritis affects the body in different ways depending on the type. The underlying mechanisms can involve wear and tear, autoimmunity, or metabolic processes. This article explores the pathophysiology of various types of arthritis.
Osteoarthritis (OA):
Cartilage Degradation: In OA, the protective cartilage that cushions the ends of bones gradually breaks down. As the cartilage erodes, bones begin to rub against each other, causing pain, swelling, and stiffness.
Bone Changes: As cartilage wears away, the body tries to repair the damage by forming new bone. However, this can result in bone spurs, which further restrict joint movement and cause pain.
Synovial Inflammation: Though OA is not primarily an inflammatory disease, the joint lining (synovium) can become inflamed, contributing to symptoms.
Rheumatoid Arthritis (RA):
Autoimmune Response: In RA, the immune system mistakenly attacks the synovium, the lining of the joints, causing inflammation. This results in the thickening of the synovium, which can eventually lead to the destruction of cartilage and bone within the joint.
Systemic Effects: RA is a systemic disease, meaning it can affect other parts of the body, including the skin, eyes, lungs, and cardiovascular system. The inflammation can cause a range of symptoms, from fatigue to more severe complications like heart disease.
Gout:
Uric Acid Crystals: Gout is caused by the buildup of uric acid in the bloodstream, which can form sharp crystals that accumulate in joints, particularly in the big toe. These crystals trigger intense inflammation, leading to severe pain, redness, and swelling.