Causes of osteoarthritis

As part of normal life, your joints are exposed to a constant low level of damage. In most cases, your body repairs the damage itself and you don’t experience any symptoms.

But in osteoarthritis, the protective cartilage on the ends of your bones breaks down, causing pain, swelling and problems moving the joint. Bony growths can develop, and the area can become inflamed (red and swollen).

The exact cause isn’t known, but several things are thought to increase your risk of developing osteoarthritis, including:

• joint injury – overusing your joint when it hasn’t had enough time to heal after an injury or operation
• other conditions (secondary arthritis) – osteoarthritis can occur in joints severely damaged by a previous or existing condition, such as rheumatoid arthritis or gout
• age – your risk of developing the condition increases as you get older
• family history – osteoarthritis may run in families, although studies haven’t identified a single gene responsible
• obesity – being obese puts excess strain on your joints, particularly those that bear most of your weight, such as your knees and hips