Osteoarthritis This is the most common kind of arthritis in the UK. It’s sometimes called 'wear and tear' arthritis and becomes more likely as a person gets older. However, younger people can be affected too.

In this article

What causes it?

What happens?

What does it feel like?

It's estimated that around 8 million people in the UK have osteoarthritis and that about one million of these request treatment. There is no single cause, but several factors seem to increase the likelihood of getting the disease:

• Age - osteoarthritis becomes more likely with increasing age and is uncommon before the age of 40
• Sex - osteoarthritis is more common in women
• Weight - being overweight increases the risk of osteoarthritis, particularly of the knee
• Injury - an injury, operation, earlier disease or repeated strain at a joint may lead to osteoarthritis later in life

In osteoarthritis, the smooth cartilage that takes the strain in a normal joint becomes rough, brittle and weak. To compensate, the bone beneath thickens and spreads out, forming knobbly outgrowths (osteophytes). The synovial membrane surrounding the joint thickens and the fluid-filled space within it becomes smaller. There is often inflammation.

As osteoarthritis gets worse, bits of cartilage may break away from the bone, causing the bone ends to rub together and the ligaments to become strained. This causes a lot of pain and changes the shape of the joint.

Osteoarthritis is most common in the hands, knees, hips and feet. Some people also develop it in the back and neck.

Osteoarthritis develops differently from person to person. The condition typically causes joints to become stiff and painful to move, but it doesn't usually cause symptoms outside the area of the joint.

It usually develops slowly and the changes can be so gradual that people hardly notice them. The condition usually settles down after a number of years and, although the joints may have a knobbly appearance, they may become less painful.

This article was last medically reviewed by Dr Rob Hicks in July 2008.
First published in October 1999.