Osteoarthritis

Overview

Osteoarthritis is the most common form of arthritis. It develops when the smooth cartilage that cushions the ends of the bones within a joint gradually roughens and thins, and the joint as a whole — the cartilage, the underlying bone, and the surrounding tissues — changes in response. It most often affects the knees, hips, hands, and lower spine.

Osteoarthritis is often described as “wear and tear”, but that phrase is misleading. The joint is not simply wearing out; it is actively trying to repair itself, and osteoarthritis is the result when that repair does not keep pace with the changes. This is why it is not an inevitable part of ageing and why treatment can genuinely help rather than merely delay the inevitable.

The impact varies widely. Some people have changes visible on an X-ray but few symptoms, while others have considerable pain from relatively modest changes. Because of this, treatment is guided by how the joint feels and functions in daily life, not by the X-ray alone.

Symptoms

The main symptoms are joint pain and stiffness. The pain is typically worse with use and towards the end of the day, and better with rest. Stiffness is common after periods of inactivity but tends to ease within about half an hour of getting moving — a useful point that helps distinguish it from inflammatory arthritis, where morning stiffness lasts much longer.

Affected joints may feel less flexible, give a grating or crackling sensation when moved, and look knobbly from bony swelling — particularly noticeable in the small joints of the hands. Symptoms usually build up slowly over months or years and can fluctuate, with better and worse spells. Osteoarthritis does not usually cause the marked warmth, redness, or prolonged morning stiffness seen in inflammatory joint disease.

Causes and risk factors

Osteoarthritis arises from a combination of factors that affect how well a joint maintains itself. Age is the strongest, and it is more common in women. Excess weight is one of the most important and changeable risks, particularly for the knees, because it increases both the load on the joint and the low-grade inflammation that contributes to the process.

A previous joint injury or operation, occupations or activities involving heavy repetitive loading, and a family history all raise the risk. The shape and alignment of a joint matter too. Osteoarthritis is not caused by ordinary exercise; in fact regular activity protects joints, and inactivity does more harm.

Diagnosis

Osteoarthritis is usually diagnosed from the symptoms and a physical examination, without the need for tests. In a person over about 45 with activity-related joint pain and no prolonged morning stiffness, the diagnosis can be made confidently on the clinical picture alone.

X-rays are not needed to make the diagnosis and are used mainly when the picture is unclear or to help plan treatment such as surgery. Importantly, X-ray changes correlate poorly with pain — significant changes can cause few symptoms, and vice versa — so treatment follows the person’s experience rather than the image. Blood tests are normal in osteoarthritis and are used only to exclude other kinds of arthritis when there is doubt.

Investigations

In most cases no investigations are required. Where tests are used, X-rays can show narrowing of the joint space and other characteristic changes, and blood tests may be done to rule out inflammatory arthritis when the distinction is uncertain. Extensive scanning is generally unnecessary and rarely changes what is recommended.

The focus of assessment is functional: how the joint moves, how much pain limits daily activities, and which tasks a person struggles with. This is what guides treatment and what is followed over time to judge whether it is helping.

Treatment

The most effective treatments for osteoarthritis are not medicines. Regular exercise — combining activities that improve fitness with specific exercises to strengthen the muscles around the joint — reliably reduces pain and improves function, and is recommended for everyone with the condition. It commonly feels counter-intuitive to exercise a painful joint, but doing so, sensibly and consistently, protects and supports it.

Losing excess weight makes a substantial difference, particularly for the knees and hips. Simple measures such as suitable footwear, walking aids, and pacing help daily life. For pain relief, topical anti-inflammatory gels are often tried first, with other pain relievers used carefully and for the shortest time needed. Steroid injections can give short-term relief during a bad spell. When osteoarthritis of the hip or knee severely limits life despite these measures, joint replacement surgery is a highly effective option that relieves pain and restores function for the great majority of people.

Living with osteoarthritis

Keeping active is the cornerstone of living well with osteoarthritis. Regular, gentle exercise maintains the strength and flexibility that protect the joint, and usually reduces pain over time rather than increasing it. Building activity into a daily routine, and keeping the muscles around affected joints strong, pays off in the long run.

Maintaining a healthy weight takes strain off weight-bearing joints, and pacing demanding tasks helps avoid flare-ups of pain. Osteoarthritis is a long-term condition, but it is not relentlessly progressive for everyone, and with the right combination of exercise, weight management, and — where needed — medical or surgical treatment, most people keep good use of their joints and stay independent.