Causes of osteoarthritis 

Osteoarthritis occurs when there is damage in and around the joints that the body can't fully repair. The exact causes are not known but there are several factors thought to increase your risk of developing the condition.

As part of normal life, your joints are exposed to a constant low level of damage. In most cases, your body will repair the damage itself. Usually, the repair process will pass unnoticed and you will not experience any symptoms.

However, in cases of osteoarthritis, the damage to the joints is not fully repaired and instead some of the cartilage (the protective surface that allows your joints to move smoothly) in the joint can be lost, bony growths can develop, and the area can become slightly inflamed (red and swollen).

These changes are what cause the typical symptoms of pain, stiffness and swelling.

Contributory factors

It is not known why problems develop in the repair process in cases of osteoarthritis, although, several factors are thought to increase your risk of developing the condition. These include:

  • Joint injury – Osteoarthritis can develop in a joint damaged by an injury or operation. Overusing your joint when it has not had enough time to heal after an injury or operation can also contribute to osteoarthritis in later life.
  • Other conditions (secondary arthritis) – Sometimes, osteoarthritis can occur in joints severely damaged by a previous or existing condition, such as rheumatoid arthritis or gout. It is possible for secondary osteoarthritis to develop many years after the initial damage to your joint.
  • Age – Osteoarthritis is not a normal part of ageing, but your risk of developing the condition does increase as you get older. Most cases affect adults who are 45 years of age or older.
  • Family history – In some cases, osteoarthritis may run in families. Genetic studies have not identified a single gene responsible, so it seems likely that many genes make small contributions.
  • Obesity – Research into the causes of osteoarthritis has shown that being obese puts excess strain on your joints, particularly those that bear most of your weight, such as your knees and hips. As a result, osteoarthritis can often be worse in obese people.

Although it is not possible to prevent osteoarthritis altogether, making some lifestyle changes to reduce your risk of joint injury and maintain a healthy weight may lower your chances of developing the condition.

Read more about preventing osteoarthritis.


Page last reviewed: 27/08/2014

Next review due: 27/08/2016