Medically Reviewed

Knee Pain

Symptoms, Causes & Treatment

Understanding knee pain: what causes it, how it is investigated, and the most effective treatments from physiotherapy to surgery.

Book My Consultation
Learn More
Licensed UK clinicians
Same-day prescriptions, where clinically appropriate
Delivered to your door within 24 hours
What our patients say
4.7 out of 5
Easy and efficient! … I am on the mend and so glad this service exists.
Pete Garvey
Excellent. Started to feel unwell and needed to see Dr before going on holiday. Couldn't get' GP appointment in time. I was 'seen' within 30mins of signing up. Just picked up a prescription. Very impressed with the Dr Victoria White.
Iann de Courcy
Fantastic service received from the gp service. Easy to book consultation… Would definitely use again :- )
Jay
Fantastic service. Easy to sign up and instructions were very clear. My doctor, Dr Shakil David Alam was amazing; listened to my issues, gave me in depth advice and really helped me out. Would definitely reuse - the speed of the service was impressive. Thank you Dr Shakil.
Babac Pashazadeh
I'm not someone who posts reviews regularly, but I have to say the process was super smooth. Booked a same day appointment with a clearly experienced and friendly doctor…
Yardie Grandmaster
Excellent service - quick, professional, and really convenient. The doctors are thorough and the whole process is smooth from start to finish. Highly recommend.
Mohammad Hassan
What our patients say
4.7 out of 5
Easy and efficient! … I am on the mend and so glad this service exists.
Pete Garvey
Excellent. Started to feel unwell and needed to see Dr before going on holiday. Couldn't get' GP appointment in time. I was 'seen' within 30mins of signing up. Just picked up a prescription. Very impressed with the Dr Victoria White.
Iann de Courcy
Fantastic service received from the gp service. Easy to book consultation… Would definitely use again :- )
Jay
Fantastic service. Easy to sign up and instructions were very clear. My doctor, Dr Shakil David Alam was amazing; listened to my issues, gave me in depth advice and really helped me out. Would definitely reuse - the speed of the service was impressive. Thank you Dr Shakil.
Babac Pashazadeh
I'm not someone who posts reviews regularly, but I have to say the process was super smooth. Booked a same day appointment with a clearly experienced and friendly doctor…
Yardie Grandmaster
Excellent service - quick, professional, and really convenient. The doctors are thorough and the whole process is smooth from start to finish. Highly recommend.
Mohammad Hassan
Overview

What Is Knee Pain?

Knee pain is one of the most common musculoskeletal complaints affecting people of all ages. In younger patients, sports injuries — ACL tears, meniscal tears, and patellofemoral pain syndrome — predominate. In older patients, osteoarthritis is the most common cause.

The knee is a complex joint with multiple structures that can be injured or degenerate. Accurate assessment of which structure is causing pain determines the appropriate treatment.

Symptoms

What Are the Symptoms of Knee Pain?

The location, onset, and associated features of knee pain are the key diagnostic features.

Knee Pain Symptoms

Knee pain localised to front, side, or back of knee · Swelling or effusion (fluid in knee) · Locking or giving way of knee · Reduced ability to fully extend or flex · Crepitus on movement · Tenderness on palpation of joint line

common
Knee Pain: When to Seek Urgent Help

Sudden knee locking after twisting (possible meniscal tear) · Haemarthrosis (rapid swelling after injury — possible ACL rupture or fracture) · Knee giving way repeatedly · Hot, red, swollen knee with fever (septic arthritis)

serious
Rapid Knee Swelling After Injury — Attend A&E

Rapid, significant knee swelling immediately after a twisting injury suggests haemarthrosis (blood in the joint) from an ACL tear or fracture. Attend A&E or orthopaedic urgent care the same day.

Causes & Risk Factors

What Causes Knee Pain?

Knee pain has numerous causes depending on age, mechanism of injury, and location of pain. Accurate anatomical localisation and history of injury or gradual onset guide the diagnosis.

Patellofemoral Pain Syndrome

Patellofemoral pain syndrome (runner's knee) is the most common cause of anterior knee pain. It results from maltracking of the patella, causing pain on stairs, squatting, and prolonged sitting.

Meniscal Tear & ACL Injury

Meniscal tears occur from twisting injuries and cause joint line tenderness, locking, and giving way. The ACL is commonly torn with pivoting injuries, producing haemarthrosis and instability. Both may require surgical management.

Osteoarthritis Mechanism

Osteoarthritis (OA) causes progressive loss of articular cartilage, subchondral bone remodelling, and osteophyte formation. It is the most common cause of chronic joint pain in adults over 50, affecting knees, hips, hands, and spine.

Rheumatoid Arthritis Pathogenesis

Rheumatoid arthritis (RA) is a systemic autoimmune disease in which the immune system attacks synovial joints, causing chronic synovitis, joint erosion, deformity, and systemic inflammation. Anti-CCP antibodies are highly specific.

Non-Specific Back Pain & Disc Disease

Non-specific low back pain (no identifiable cause) accounts for 85% of presentations. Disc herniation, facet joint degeneration, and muscle/ligament strain are the most common structural causes. Poor posture and sedentary lifestyle are key contributors.

Muscle Strain Grades & Mechanism

Muscle strains occur when muscle fibres are overstretched or torn. Grade 1 = mild stretch; Grade 2 = partial tear; Grade 3 = complete rupture. Eccentric muscle loading during sprinting, jumping, or lifting is the most common mechanism.

Key Risk Factors

Obesity / high BMI
Sports and high-impact activity
Contact sports (shoulder, knee)
Previous musculoskeletal injury
Age (degenerative changes)
Female sex (RA, OA more common)
Family history of arthritis or back pain
Tight hip flexors and hamstrings (back/knee)
Smoking (disc degeneration)
Low physical fitness / muscle weakness
Diabetes mellitus (frozen shoulder, neuropathy)
Corticosteroid use (tendon weakness)
Diagnosis

How Is Knee Pain Diagnosed?

Clinical assessment including Lachman test (ACL), McMurray test (meniscus), and effusion assessment guides investigation. Imaging is required for significant injury or when surgery is being considered.

Test
What It Detects
When Used
Musculoskeletal Ultrasound
Soft tissue injury, tendon tears, effusions, rotator cuff tears, plantar fasciitis
Shoulder, Achilles, knee assessment; guided injection; soft tissue injury
MRI (Knee / Shoulder / Spine)
Meniscal tears, ACL/PCL tears, rotator cuff tears, cartilage, disc herniation
Soft tissue injury not resolving; surgical planning; neurological deficit
X-ray (Peripheral Joints)
Fracture, joint space narrowing (OA), periarticular osteoporosis (RA), tophi (gout)
Trauma; suspected fracture; chronic joint disease assessment; Ottawa rules positive
Joint Aspiration (Arthrocentesis)
Septic arthritis (turbid fluid, organisms on Gram stain), gout (urate crystals), haemarthrosis
Hot, red, swollen joint with fever; suspected gout or pseudogout; diagnostic uncertainty
Rheumatoid Factor & Anti-CCP
Rheumatoid arthritis; anti-CCP is highly specific and predicts erosive disease
Suspected RA; symmetrical small joint polyarthritis with morning stiffness
Gait Analysis & Podiatry Assessment
Biomechanical abnormalities, overpronation, leg length discrepancy, footwear problems
Chronic foot, knee, or back pain; suspected biomechanical cause
Treatment Options

How Is Knee Pain Treated?

Treatment ranges from conservative physiotherapy for most presentations to surgical reconstruction for complete ligament ruptures and knee replacement for severe OA.

Antibiotic
Typical Use
Standard Course
RICE Protocol (Acute Injury)
Acute sprains and muscle strains; reduces swelling and pain
Rest, Ice (20 min on/20 min off), Compression bandage, Elevation; first 48–72 hours
NSAIDs (Ibuprofen, Naproxen)
First-line analgesia for musculoskeletal pain; acute gout; back pain; joint pain
Ibuprofen 400mg three times daily with food; naproxen 500mg twice daily; maximum 2 weeks continuous
Paracetamol
Baseline analgesia for MSK pain; used when NSAIDs contraindicated
500–1000mg up to four times daily; maximum 4g per day
Physiotherapy & Exercise Therapy
Back pain, joint pain, sciatica, shoulder, knee — most effective treatment for chronic MSK conditions
6–12 weeks of structured physiotherapy; core strengthening, stretching, graded exercise
Intra-articular Corticosteroid Injection
OA, frozen shoulder, knee effusion, gout — rapid short-term pain relief
Single injection; repeat maximum 3–4 times per year per joint
Orthotic Insoles (Foot / Back Pain)
Plantar fasciitis, flat feet, overpronation, leg length discrepancy
Custom or off-the-shelf; wear daily; review at 3–6 months

Supportive Measures

RICE for acute injuries, NSAIDs for inflammation, quadriceps and hip strengthening exercises for patellofemoral pain, and weight management for OA are the most effective self-management strategies.

When Knee Pain Needs Specialist Review

Recurrent knee pain not controlled with physiotherapy and analgesia warrants specialist orthopaedic review. For OA, knee replacement is highly effective at restoring function and quality of life. For ligament injuries with persistent instability, surgical reconstruction may be appropriate.

When to Seek Help

When Should You Seek Medical Advice for Knee Pain?

Seek Emergency Care (999 / A&E) If:

Sudden knee haemarthrosis (rapid significant swelling after injury) — possible ACL rupture or fracture · Hot, swollen knee with fever (septic arthritis) · Complete knee locking unable to extend · Inability to weight bear after trauma.

See a Clinician the Same Day If:

Sudden significant knee swelling after injury · Knee locking and inability to fully extend · Hot, swollen knee with fever · Knee giving way repeatedly · OA pain not controlled with analgesia and physiotherapy.

Prevention

How to Protect Your Knees

Knee pain prevention focuses on maintaining strong muscles around the joint, healthy weight, and appropriate training load.

Injury Prevention Through Warm-Up

Warm up adequately before exercise and cool down after. Increase training load gradually (the 10% rule). Strengthen muscles around vulnerable joints (glutes for knee, rotator cuff for shoulder, core for back) to reduce injury risk.

Weight Management for Joint Health

Weight management reduces load on weight-bearing joints. Every 1kg of body weight loss reduces knee joint loading by 4kg. Low-impact exercise (swimming, cycling) maintains fitness without joint stress.

Exercise & Physiotherapy (Joint Pain)

Physiotherapy-led exercise is more effective than rest for most MSK conditions. Strengthening exercises for the muscles around affected joints reduce pain and improve function. Ask for a referral or self-refer where available.

Proprioception Training (Ankle Sprain)

Proprioception (balance) retraining after ankle sprain significantly reduces recurrence risk. Simple exercises: single-leg standing, wobble board training — start while holding support and progress to unsupported over 4–6 weeks.

Core & Muscle Strengthening

Maintain strong, flexible muscles around the spine and joints. Core strengthening (Pilates, swimming), hip strengthening (glute exercises), and hamstring stretching are the most evidence-based approaches for back pain and sciatica prevention.

Footwear for Foot Pain & Plantar Fasciitis

Supportive footwear with good arch support and cushioning is the most important non-pharmacological treatment for plantar fasciitis. Avoid walking barefoot on hard floors, especially in the morning. Replace sports shoes every 500 miles.

Getting Treatment

Speak to a Clinician About Knee Pain

Through The GP Service, a licensed clinician can assess your knee pain, arrange investigations, recommend physiotherapy, and refer to orthopaedics where appropriate.

Woman sitting on a couch using a mobile app with a calendar and timer interface on the screen.
1
Book Your Appointment
Book to see a consultant online the same day, at a time that suits you.
Open 365 days a year, 8am - 5pm
Same-day appointments available
Smiling male doctor wearing a white coat and stethoscope holding a tablet in a hospital corridor.
2
See a Consultant
Speak to one of our licensed medical professionals from anywhere - using a phone, computer, or tablet.
Request prescriptions
Request Fit Notes
Request Referral Letters
Pharmacist wearing a white coat smiling and explaining medication to a female customer in a pharmacy.
3
Book a Consultation
Within minutes of your consultation, receive prescriptions, fit notes, or referral letters where clinically appropriate.
Collect prescriptions within an hour of issue
Pick up from ANY pharmacy
Shared with your medical records & NHS GP

Expert clinical advice, when you need it.

See a licensed clinician online in minutes. If treatment is clinically right for you, your prescription will be sent to your pharmacy the same day.
Book My Consultation
No waiting room
Delivered to your door within 24 hours
Open 365 days a year
Licensed UK clinicians
Secure & confidential
Frequently Asked Questions

Knee Pain FAQs

Do I need surgery for my shoulder?

Most rotator cuff problems — tendinopathy, partial tears, and impingement — respond well to physiotherapy. A targeted physiotherapy programme addressing rotator cuff strength and scapular control resolves 70–80% of cases within 3–6 months. Steroid injection provides short-term relief but does not improve long-term outcomes. Full-thickness rotator cuff tears with significant weakness warrant MRI assessment and possible surgical repair, especially in younger or active patients. Frozen shoulder runs a natural history of 1–3 years and usually resolves fully without surgery.

When is joint pain an emergency?

Joint pain with a hot, red, severely swollen joint and fever is a red flag for septic arthritis — a surgical emergency. This requires same-day joint aspiration and IV antibiotics. Joint pain without these features requires investigation to determine the cause: OA, RA, gout, or reactive arthritis. Getting the right diagnosis quickly matters because RA causes joint erosion within weeks to months of onset, and early DMARD treatment dramatically reduces long-term disability.

What is the difference between OA and RA?

OA affects cartilage and causes pain that worsens with use and eases with rest. RA is an autoimmune disease causing symmetrical synovial inflammation, morning stiffness >1 hour, systemic symptoms, and elevated inflammatory markers. RA gets worse without treatment and causes irreversible joint destruction; OA does not have systemic consequences. Getting the right diagnosis early is important because the treatments are completely different. If you have morning stiffness lasting over an hour and symmetrical joint swelling, see a clinician urgently for RA screening.

Is my back pain serious?

Most back pain is non-specific — caused by muscle, ligament, or disc strain without any serious underlying cause. The vast majority resolves within 4–6 weeks. Key red flags to watch for: bladder or bowel changes (possible cauda equina syndrome — call 999), fever, unexplained weight loss, or pain that is unrelenting at night regardless of position. If none of these are present, staying active, taking regular analgesia, and seeing a physiotherapist is the most effective approach.

How long does back pain last?

Bed rest is not recommended and actually slows recovery. Staying as active as pain allows — walking, gentle stretching, swimming — helps the back heal faster. Most non-specific back pain improves within 4–6 weeks with movement, NSAIDs, and physiotherapy. Seeing a physiotherapist early produces better outcomes than waiting. If back pain has not improved after 6 weeks, or is worsening, a GP review is warranted to consider imaging and further management.

Will sciatica get better on its own?

Sciatica is caused by compression of the sciatic nerve or its nerve roots — most commonly from a disc herniation at L4/5 or L5/S1. Around 80–90% of sciatica resolves within 6–12 weeks with conservative management: staying active, NSAIDs, physiotherapy, and nerve pain medication if needed. Red flags requiring emergency assessment: loss of bladder or bowel control, saddle numbness, or rapidly progressive leg weakness. These could indicate cauda equina syndrome, which is a surgical emergency.

When should I take allopurinol?

Allopurinol should never be started during an acute gout attack as this can prolong or worsen the flare. It should be started 2–4 weeks after the acute attack has settled, ideally while continuing prophylactic colchicine or NSAID cover for the first 3–6 months. Start at 100mg daily and increase every 4 weeks to achieve a target serum urate below 360 μmol/L. Once on a stable dose, allopurinol is continued indefinitely. Stopping and restarting is a common cause of recurrent attacks.

How long does a sprained ankle take to heal?

Most ankle sprains heal within 6–8 weeks. Grade 1 (stretching) and Grade 2 (partial tear) injuries resolve with physiotherapy and graded return to sport. Grade 3 (complete ligament rupture) may require immobilisation or, rarely, surgery. Proprioception training is essential to prevent recurrence — recurrent ankle sprains dramatically increase long-term instability and OA risk. If you cannot weight bear after an ankle injury, apply the Ottawa rules: inability to weight bear plus bony tenderness at the malleolus warrants an X-ray to exclude fracture.

Medical Disclaimer: The information on this page is provided for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare professional with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay seeking it because of something you have read on this page. If you think you may have a medical emergency, call 999 or your local emergency services immediately.