Knee pain is one of the most common musculoskeletal complaints in the UK, affecting people of all ages — from young athletes to older adults. It can develop suddenly after an injury or gradually over time, and its impact ranges from mild discomfort to severe disability that interferes with walking, working, and sleep.
Because the knee is a complex joint that bears much of the body’s weight, it is vulnerable to strain, degeneration, and injury. Understanding the possible causes — and knowing when to seek medical help — is key to effective treatment and long-term joint health.
Why Knee Pain Happens
The knee joint connects the thigh bone (femur) to the shin bone (tibia) and is supported by ligaments, tendons, cartilage, muscles, and fluid-filled sacs that allow smooth movement. Damage or inflammation in any of these structures can produce pain.
Pain may be felt at the front, back, inside, or outside of the knee, and the location often provides clues about the underlying problem. Some people experience stiffness or swelling, while others feel instability or weakness when bearing weight.
Common Causes of Knee Pain
Osteoarthritis
Osteoarthritis is the most frequent cause of chronic knee pain in the UK, particularly among people over 50. It occurs when the protective cartilage that cushions the joint gradually wears away, causing bones to rub together.
Symptoms often develop slowly and may include stiffness in the morning, aching after activity, reduced range of motion, and swelling. Pain may worsen with walking, climbing stairs, or standing for long periods.
More information from the NHS:
https://www.nhs.uk/conditions/osteoarthritis/
Ligament Injuries
The knee contains several important ligaments that stabilise the joint. Sudden twisting movements, sports injuries, or accidents can stretch or tear these structures.
The anterior cruciate ligament (ACL) is particularly prone to injury, especially in sports involving rapid direction changes such as football or skiing. A ligament tear may cause immediate pain, swelling, instability, and difficulty bearing weight.
Meniscus Tears
The menisci are cartilage pads that act as shock absorbers between the thigh and shin bones. They can tear during sudden twisting motions or as a result of age-related degeneration.
A torn meniscus may produce sharp pain, swelling, locking or catching of the knee, and difficulty straightening the leg fully. In older adults, these tears often occur with minimal trauma.
Tendon Problems
Overuse or repetitive strain can irritate the tendons around the knee. Patellar tendinopathy — sometimes called “jumper’s knee” — commonly affects athletes but can also occur in people who kneel frequently or increase activity levels suddenly.
Pain is usually localised below the kneecap and worsens with activity such as jumping, running, or climbing stairs.
Bursitis
Small fluid-filled sacs called bursae cushion the knee joint. When inflamed, they can cause swelling, tenderness, and warmth around the joint. Bursitis often develops from prolonged kneeling, repetitive pressure, or minor injury.
Patellofemoral Pain Syndrome
This condition causes pain at the front of the knee around the kneecap. It is common in younger adults and runners and is often linked to muscle imbalance, overuse, or alignment issues.
People may notice discomfort when sitting for long periods, squatting, or descending stairs.
Other Possible Causes
Knee pain may also result from inflammatory conditions such as rheumatoid arthritis, gout, or infection. Less commonly, referred pain from the hip or lower back can be felt in the knee.
Because causes vary widely, persistent pain should be assessed by a healthcare professional.
Symptoms That Need Urgent Attention
While many knee problems improve with rest and self-care, some signs indicate a need for prompt medical evaluation.
Seek urgent help if you experience severe pain after an injury, inability to bear weight, significant swelling, deformity, or symptoms of infection such as fever and redness. Sudden locking of the knee or loss of movement also requires assessment.
Diagnosis in the UK
Assessment usually begins with a GP consultation. Your doctor will ask about symptoms, activity levels, injuries, and medical history, followed by a physical examination of the knee’s movement, stability, and swelling.
If further investigation is needed, imaging tests may be arranged. X-rays are commonly used to detect arthritis or bone problems, while MRI scans provide detailed images of soft tissues such as ligaments and cartilage.
In many cases, physiotherapists play a central role in both diagnosis and treatment. Direct access to NHS physiotherapy is available in some regions without GP referral.
Private clinics may offer faster access to imaging and specialist assessment.
Treatment Options
Treatment depends on the underlying cause, severity, and how much the pain affects daily life.
Self-Care and Lifestyle Measures
Many mild or moderate cases improve with simple measures. Resting the joint, applying ice to reduce swelling, and avoiding activities that aggravate pain can allow tissues to heal.
Weight management is particularly important for people with osteoarthritis, as excess body weight increases pressure on the knee joint. Supportive footwear and knee braces may also help stabilise the joint during activity.
Physiotherapy
Physiotherapy is often the cornerstone of knee pain management in the UK. A tailored exercise programme can strengthen muscles around the knee, improve flexibility, and restore normal movement patterns.
Exercises targeting the quadriceps, hamstrings, and hip muscles are especially beneficial. Physiotherapists may also use techniques such as manual therapy, taping, or advice on posture and activity modification.
Medications
Pain relief options include paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, available over the counter or by prescription. Topical anti-inflammatory gels may provide relief with fewer systemic side effects.
Stronger medications may be prescribed for severe pain, but long-term use is generally avoided due to potential risks.
Injections
For persistent symptoms, injections into the knee joint may be considered. Corticosteroid injections can reduce inflammation and pain, particularly in osteoarthritis or bursitis.
Some clinics also offer hyaluronic acid injections or other treatments, although availability and evidence vary.
Guidance from NICE on osteoarthritis management:
https://www.nice.org.uk/guidance
Surgical Treatment
Surgery is usually reserved for cases where conservative treatment has failed or where structural damage is severe.
Arthroscopic (keyhole) surgery may be used to repair or remove damaged tissue in certain situations, though it is not routinely recommended for degenerative arthritis.
Knee replacement surgery is considered for advanced osteoarthritis when pain and disability significantly affect quality of life. This procedure replaces damaged joint surfaces with artificial components and can dramatically improve mobility and comfort.
Both partial and total knee replacements are performed in the UK through the NHS and private sector.
Living With Knee Pain
Chronic knee pain can affect sleep, mood, and independence. Maintaining activity within comfortable limits is important, as complete rest may lead to muscle weakness and worsening symptoms.
Low-impact activities such as swimming, cycling, and walking on even surfaces are generally recommended. Many people benefit from pacing strategies — balancing activity and rest to avoid flare-ups.
Support from physiotherapists, occupational therapists, and pain specialists can help individuals remain active and independent.
When to See a Specialist
If knee pain persists for more than a few weeks despite self-care, or if it interferes with work or daily activities, medical advice should be sought. Referral to an orthopaedic specialist may be appropriate for complex or severe cases.
Early assessment can prevent minor problems from becoming long-term conditions and allows access to treatments that may restore function and reduce pain.
Final Thoughts
Knee pain is extremely common but should not be dismissed as an inevitable part of ageing. With accurate diagnosis and appropriate treatment, most people can achieve significant improvement and continue to lead active lives.
Whether the cause is injury, overuse, or arthritis, a combination of medical care, rehabilitation, and lifestyle adjustments can protect joint health and reduce discomfort over the long term.
If you are experiencing persistent knee pain, speaking with a healthcare professional is the first step toward recovery and maintaining mobility for the future.
