Overview
Knee pain is one of the most common musculoskeletal complaints. It has many causes, ranging from acute injuries such as ligament tears and meniscal damage to chronic conditions like osteoarthritis and patellofemoral pain. Most knee pain responds to conservative management, though some injuries require surgical intervention.
How common is it?
Knee pain can affect people of any age. Injuries and overuse are common causes, while osteoarthritis is a common cause in older adults.
Causes and risk factors
Acute knee pain usually follows injury to ligaments, menisci, or bone. Chronic knee pain commonly reflects overuse, degeneration, or inflammatory arthritis.
Common risk factors
- Osteoarthritis (age-related cartilage degeneration)
- ACL, PCL, MCL, or LCL ligament tears (sports or trauma)
- Meniscal tears
- Patellofemoral pain syndrome (runner's knee)
- Iliotibial band syndrome
- Patellar tendinopathy (jumper's knee)
- Bursitis (prepatellar, infrapatellar)
- Gout or pseudogout (crystal arthropathy)
- Rheumatoid or psoriatic arthritis
- Osgood-Schlatter disease (teenagers)
Symptoms
- Pain localised to the front, inside, outside, or back of the knee depending on cause
- Swelling with effusion (fluid)
- Stiffness, especially in the morning or after rest
- Giving way or instability (ligament injuries)
- Locking or catching (meniscal tear)
- Crepitus (grinding or clicking)
When to see a doctor
Seek urgent medical assessment for severe pain, inability to move or bear weight, major swelling, deformity, locking, or a hot red knee with fever. A hot swollen joint may be infected. See a clinician if pain is not improving within a few weeks.
Diagnosis
Assessment starts with symptoms and a knee examination. Typical osteoarthritis often needs no scan. X-rays may assess injury or atypical symptoms; MRI is used selectively for soft-tissue problems. Suspected infection or gout may need joint-fluid testing.
Treatments
Physiotherapy
Vastus medialis and quadriceps strengthening, hip abductor strengthening, and gait correction are highly effective for patellofemoral pain and osteoarthritis. Core and gluteal strengthening reduces abnormal knee loading.
NSAIDs and analgesia
A topical NSAID may help knee osteoarthritis. Ask a pharmacist or clinician about suitability, especially with kidney disease, ulcers, heart disease, pregnancy or other medicines. Oral NSAIDs need additional risk assessment; paracetamol is not routinely recommended for osteoarthritis.
Intra-articular corticosteroid injection
Steroid injections may provide short-term relief, usually 2 to 10 weeks for osteoarthritis, when other options are unsuitable or ineffective. They can temporarily raise blood glucose; discuss monitoring if you have diabetes.
Surgical options
ACL reconstruction for symptomatic instability. Meniscal repair or partial meniscectomy. Total or partial knee replacement for end-stage osteoarthritis is one of the most successful elective operations in medicine.
Self-care and lifestyle
- If you are overweight and have knee osteoarthritis, supported weight loss can reduce joint strain and improve symptoms.
- Strengthen the quadriceps and hip muscles regularly
- Avoid activities that repeatedly aggravate the knee while maintaining overall fitness (cycling, swimming)
- Wear well-fitting supportive footwear for daily activities and sports
Prevention
Maintaining quadriceps and hip strength, managing body weight, and avoiding sudden increases in exercise intensity reduce knee injury and osteoarthritis risk.
Sources for targeted updates
Updated: 24 October 2026. Urgent-care guidance and the specific treatment or self-care statements corrected in this update; further corrections to urgent-care guidance, frequency, self-care. This update covers the named sections; a full review of the remaining guide is pending.