Osteoarthritis: symptoms, treatment and relief

Out of the 8 million people in the UK who suffer from arthritis, osteoarthritis is the most common

This degenerative joint disease affects the cartilage - the slippery tissue that covers the ends of bones in joints. Healthy cartilage allows bones to glide over one another and absorbs energy from the shock of physical movement. Osteoarthritis causes the surface layer of cartilage to break down and wear away. This allows bones under the cartilage to rub together, causing pain, bone swelling and loss of joint motion.

Over time, the joint may lose its normal shape. Also, bone spurs (small growths called osteophytes) may grow on the edges of the joint. Bits of bone or cartilage can break off and float inside the joint space, causing more pain and damage.

Osteoarthritis only affects joints. Rheumatoid arthritis - the second most common arthritis - affects other body parts besides joints. It also begins earlier than osteoarthritis, causes inflammation and can make the sufferer feel sick, tired and sometimes feverish.

Are you at risk?
Although some younger people get osteoarthritis from a joint injury, it most often occurs in people over 45. Since the number of older people is increasing, so is the incidence rate. Before the age of 45, more men have the condition, often the result of a sports or work injury, while after 45 osteoarthritis is more common in women.

Researchers don't yet know what causes it, but they suspect a combination of factors in the body and environment. Diet, weight and stresses on the joints from certain jobs, hobbies or other activities affect the disease and how a person reacts to it.

Researchers suspect that inheritance plays a role in 25-30 per cent of osteoarthritis cases. A gene defect affecting collagen (an important part of cartilage) appears to be a key trigger in patients with an inherited kind of osteoarthritis that starts at an early age.

The mutation weakens collagen protein, which may break or tear more easily under stress. Scientists are also looking for other genetic mutations that may be involved in osteoarthritis. In the future, a test to determine who carries the genetic defect or defects could help people to reduce their risk of developing it.

Wat are the symptoms?