Osteoarthritis explained

What happens in the joint

A healthy joint is where two bones meet, their ends covered by a smooth, slippery tissue called cartilage that lets them glide easily. In osteoarthritis, this cartilage gradually roughens and thins, and the joint tries to repair itself. Sometimes the repair works well and causes few problems. At other times it is less successful: the bone underneath thickens, small bony growths called spurs can form at the edges, and the lining of the joint may become mildly inflamed and produce extra fluid. The result can be pain, stiffness and a joint that no longer moves as smoothly. Because it is an active repair process rather than simple mechanical wearing out, symptoms can come and go and are not always in step with how the joint looks on an X-ray. This is why treatment focuses on function, not just images.

Symptoms and who is affected

The main symptoms are joint pain and stiffness. Pain is often worse with activity and towards the end of the day, and eases with rest, though later on it can occur at rest too. Stiffness is common first thing in the morning but usually loosens within about half an hour, which helps tell it apart from some other types of arthritis. Joints may creak or grate, feel swollen, or lose some of their normal movement. In the hands, small bony bumps can appear near the finger joints. Osteoarthritis becomes more common with age and is more likely in people who are overweight, who have had a joint injury, or who have a family history of it. Some jobs and sports that heavily load a joint can add to the risk. Women are affected more often, particularly in the hands and knees.

How it is diagnosed

In most cases a GP can diagnose osteoarthritis from the story and a simple examination, without needing scans. The typical picture is someone over about 45 with activity-related joint pain and morning stiffness that lasts no more than about half an hour. The doctor looks for tenderness, swelling, bony enlargement and reduced movement in the affected joint. X-rays are not usually needed to confirm the diagnosis and can be misleading, because the amount of change on an image often does not match how much pain a person feels. Blood tests are not used to diagnose osteoarthritis, but they may be done to rule out other kinds of arthritis if the picture is unclear. Getting a clear diagnosis matters because it opens the door to effective self-management and reassurance that the condition can be controlled.

Keeping active and managing weight

The single most important treatment is movement. It can feel strange to exercise a painful joint, but regular activity strengthens the muscles that support and protect the joint, keeps it flexible, improves mood and reduces pain over time. A mix of exercises to build strength, improve movement and boost general fitness works best, and a physiotherapist can tailor a programme. Low-impact activities such as walking, swimming and cycling are gentle on the joints. For anyone carrying extra weight, losing even a modest amount takes a surprising load off the knees and hips and can noticeably ease symptoms. Supportive footwear, and occasionally a walking aid or simple gadgets that make daily tasks easier, all help. The aim is to stay independent and active rather than to rest the joint, which tends to make stiffness and weakness worse.

Treatments and when to seek more help

Alongside exercise and weight management, several treatments ease pain. Applying heat or cold, and pain-relieving gels or tablets recommended by a pharmacist or GP, can help during flare-ups; medicines should be used at the lowest amount that works and reviewed regularly. Some people benefit from a course of physiotherapy or from learning pacing techniques that balance activity and rest. A joint injection may be offered to settle a bad flare in some cases. When osteoarthritis of the hip or knee is severe, causing pain that disturbs sleep and seriously limits daily life despite these measures, a GP can refer you to consider joint replacement surgery, which is very successful for many people. Speak to your GP if pain is worsening, a joint suddenly becomes hot, swollen and very painful, or your usual treatments are no longer controlling symptoms.