Joint Pain — Causes, Assessment, Diagnosis & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Joint pain (arthralgia) is pain arising from one or more joints — the articulations between bones — and is one of the most prevalent complaints in both primary and secondary healthcare worldwide. Musculoskeletal disorders collectively affect 1.71 billion people globally and represent the leading cause of years lived with disability (YLDs). Joint pain may arise from intra-articular structures (articular cartilage, synovium, joint capsule, subchondral bone, intra-articular ligaments) or periarticular structures (tendons, bursae, ligaments, entheses, and periosteum) — the distinction between these two patterns is clinically important. Joint pain must be assessed systematically to determine the most likely cause, as the aetiology determines appropriate treatment: osteoarthritis (the most common cause — degenerative cartilage loss); inflammatory arthritis (rheumatoid arthritis — autoimmune synovitis; psoriatic arthritis — enthesitis and inflammatory synovitis; ankylosing spondylitis — axial and sacroiliac inflammation; reactive arthritis; systemic lupus erythematosus); crystal arthropathy (gout — monosodium urate crystal deposition; pseudogout/calcium pyrophosphate deposition — CPPD); septic arthritis (bacterial joint infection — a medical emergency); viral arthritis (parvovirus B19, chikungunya, hepatitis B and C); and systemic diseases with joint involvement (sarcoidosis, inflammatory bowel disease). The clinical approach to joint pain — single joint (monoarthritis) vs multiple joints (oligoarthritis or polyarthritis), acute vs chronic, mechanical vs inflammatory pattern — determines the differential diagnosis and diagnostic pathway.

Joint pain causes are best understood through a systematic classification. Degenerative/mechanical causes: osteoarthritis (OA) — the most common joint disease; results from progressive breakdown of articular cartilage, subchondral bone remodelling, osteophyte formation, and synovitis; risk factors include increasing age, female sex, obesity (each 5 kg/m2 increase in BMI increases knee OA risk by 35%), previous joint injury, occupational factors (repetitive kneeling, squatting), and genetics (50% heritability for hip and knee OA). Inflammatory arthritis (autoimmune and immune-mediated): rheumatoid arthritis (RA) — autoimmune synovitis; symmetric small joint polyarthritis (MCP, PIP, wrist); anti-CCP antibodies (95% specific) and RF (70-80% sensitive); TNF, IL-6, IL-1 cytokine cascade drives joint destruction; psoriatic arthritis (PsA) — occurs in 25-35% of psoriasis patients; asymmetric oligoarthritis, DIP joint involvement, enthesitis, dactylitis, and axial disease; ankylosing spondylitis/axial spondyloarthropathy (AS/axSpA) — HLA-B27 associated; sacroiliac joint and spinal inflammation causing inflammatory back pain; reactive arthritis (formerly Reiter's syndrome) — sterile arthritis triggered by genitourinary (chlamydia) or GI infection (Salmonella, Shigella, Campylobacter); lupus arthritis — non-erosive polyarthritis in SLE. Crystal arthropathy: gout — monosodium urate (MSU) crystals depositing in joints and soft tissues; predominantly metatarsophalangeal joint of the big toe (podagra), ankles, knees; associated with hyperuricaemia, renal disease, diuretic use, and dietary purines (red meat, organ meats, shellfish, alcohol — especially beer); CPPD (pseudogout) — calcium pyrophosphate crystals; knee most commonly affected; associated with hyperparathyroidism, haemochromatosis, hypothyroidism. Septic arthritis: Staphylococcus aureus (most common), Neisseria gonorrhoeae (young sexually active adults), Streptococcus spp., and gram-negative organisms; single hot, swollen, painful joint requiring emergency joint aspiration and IV antibiotics. Viral arthritis: parvovirus B19 (symmetric small joint polyarthritis), chikungunya (acute severe polyarthritis — resolves in weeks but can be prolonged), hepatitis B (prodrome polyarthritis), rubella, HIV.

The pattern of joint pain provides critical diagnostic clues. Mechanical joint pain (osteoarthritis): worse with activity, particularly weight-bearing; improves with rest; morning stiffness brief (below 30 minutes); bony enlargement (Heberden's nodes at DIP, Bouchard's nodes at PIP in hand OA; joint-line tenderness in knee OA); crepitus on movement; no systemic features (no fever, weight loss). Inflammatory joint pain: worse in the morning — prolonged morning stiffness above 1 hour is the hallmark; improves with activity and gets worse with rest; swelling from synovitis (boggy, warm joint swelling — not just bony); associated systemic features — fatigue, malaise, low-grade fever, weight loss; symmetry (RA) or asymmetry (PsA, reactive arthritis). Gout: acute onset (typically overnight) of severe monoarthritis — exquisitely painful, hot, red, swollen joint; first MTP joint (podagra) is the classic site (50% of attacks); cannot bear pressure even from bedsheet; spontaneously resolves in 7-10 days without treatment; triggers: alcohol binge, dehydration, diuretics, surgery, acute illness. Septic arthritis: single hot, swollen, very tender joint; systemic sepsis features (fever, rigors, elevated WBC, CRP); inability to weight-bear or move joint; risk factors — immunosuppression, prosthetic joint, skin breaks (injecting drug use, recent joint injection). Number and distribution of joints: monoarthritis (one joint) — gout, septic arthritis, trauma, haemarthrosis; oligoarthritis (2-4 joints) — PsA, reactive arthritis, Lyme disease; polyarthritis (5+ joints) — RA, SLE, viral, early PsA; large joint predominance (knee, hip, ankle) vs small joint predominance (MCP, PIP, wrist — RA).

Clinical assessment: detailed history — duration, joint distribution, pattern (mono/oligo/polyarthritis), symmetry, morning stiffness duration, triggering and relieving factors, associated features (skin — psoriasis; eyes — uveitis; bowel — IBD; genitourinary — recent urethritis or cervicitis suggesting reactive arthritis; nodules — RA; tophi — gout). Full joint examination: assess each symptomatic joint for swelling (synovial thickening vs effusion vs bony — distinguish by palpation), warmth, erythema, tenderness, range of motion, and periarticular structures (tendons, bursae, entheses). Blood tests: full blood count (FBC — anaemia of chronic disease in inflammatory arthritis; leukocytosis in septic arthritis); inflammatory markers (CRP, ESR — elevated in inflammatory arthritis and infection; normal in OA); uric acid (elevated in gout — note: can be normal during an acute attack); rheumatoid factor (RF — present in 70-80% of RA, but non-specific — also elevated in other inflammatory conditions, infections, older adults); anti-cyclic citrullinated peptide antibody (anti-CCP — 95% specific for RA — the most specific RA blood test); antinuclear antibody (ANA) and anti-dsDNA (SLE); HLA-B27 (ankylosing spondylitis — positive in 85-95% of AS vs 6-8% of the general population); serum complement (C3, C4 — consumed in SLE, cryoglobulinaemia). Joint aspiration (arthrocentesis): essential for monoarthritis to exclude septic arthritis and crystal arthropathy — synovial fluid analysis: appearance (clear, turbid, bloody), cell count (WBC above 50,000/µL suggests infection; 5,000-50,000 is inflammatory), Gram stain and culture (septic arthritis), polarised light microscopy for crystals (negatively birefringent MSU crystals — gout; weakly positively birefringent CPPD crystals — pseudogout). Imaging: plain X-rays — identify OA (joint space narrowing, osteophytes, subchondral sclerosis) and gout (overhanging edge erosion); MRI — most sensitive for synovitis, early erosions, cartilage damage, bone oedema; ultrasound — identifies synovitis, effusions, enthesitis, and guides aspiration and injection; CT — bony detail (sacroiliac joint erosion in AS); dual-energy CT (DECT) — gold standard for identifying urate crystal deposits in gout.

Treatment is guided by the underlying cause — misdiagnosis leads to ineffective or harmful treatment. Osteoarthritis management: NICE recommends an active self-management approach — exercise therapy is the cornerstone (strengthening and aerobic exercise — reduces knee OA pain by 40-50%; swimming, cycling, water aerobics for low-impact conditioning); weight loss (every kg lost reduces knee loading by 3-4 kg); paracetamol (limited evidence as monotherapy but widely used); topical NSAIDs (diclofenac gel — first-line pharmacological treatment for knee OA per NICE — effective and minimal systemic absorption); oral NSAIDs (ibuprofen, naproxen — for moderate-to-severe OA pain unresponsive to paracetamol and topical NSAIDs; gastroprotect with PPI); intra-articular corticosteroid injections (methylprednisolone — short-term benefit for effusion and pain; limit to 3-4 per year); hyaluronic acid injections (limited evidence — not routinely recommended by NICE); total knee or hip replacement — for severe OA with functional limitation not responding to conservative management; success rates above 90% for pain relief. Inflammatory arthritis (RA): early diagnosis and treatment within 3 months of symptom onset prevents joint destruction; methotrexate (MTX — gold standard DMARD; 15-25 mg weekly oral or SC with folic acid 5 mg once weekly; LFT monitoring; avoid in severe renal/hepatic disease); sulfasalazine (2-3 g/day); hydroxychloroquine; leflunomide; treat-to-target strategy — aiming for remission or low disease activity (DAS28 below 2.6 or 3.2 respectively); biological DMARDs (bDMARDs) for MTX failure — TNF inhibitors (adalimumab SC every 2 weeks, etanercept SC weekly, infliximab IV; most used first-line bDMARD); IL-6 inhibitors (tocilizumab — particularly effective for high inflammatory burden and anaemia of chronic disease); JAK inhibitors (tofacitinib, baricitinib, upadacitinib — oral; efficacy comparable to biologics; monitoring for serious infections, thrombosis, cardiovascular events). Gout: acute attack — colchicine 500 µg 2-4x daily (first-line; reduce dose in renal impairment), NSAIDs at full dose for 7-10 days, or prednisolone 30 mg daily for 5 days if colchicine and NSAIDs contraindicated; do not stop urate-lowering therapy during acute attack; urate-lowering therapy (ULT) — allopurinol (100-900 mg daily; titrated against serum urate to target below 360 µmol/L — below 300 µmol/L for tophaceous gout; start low 100 mg and titrate to avoid triggering acute attacks); febuxostat (alternative xanthine oxidase inhibitor — more potent but cardiovascular safety signal; use with caution); pegloticase (IV uricase — for refractory tophaceous gout). Septic arthritis: immediate joint washout (arthroscopic or open lavage for large joints — knee, hip, shoulder) plus prolonged IV antibiotics (flucloxacillin for MSSA; vancomycin for MRSA/penicillin allergy; ceftriaxone for gonococcal arthritis); orthopaedic emergency — joint destruction occurs within 24-48 hours without drainage.

Untreated or inadequately treated joint conditions cause serious, often irreversible complications. Joint destruction: inflammatory arthritis (RA, PsA) without DMARD treatment causes progressive erosive arthropathy — articular cartilage destruction, subchondral bone erosion, and joint deformity (ulnar deviation, swan-neck deformity, boutonnière deformity in RA) leading to permanent functional disability; early DMARD therapy prevents erosion in the majority of patients when started within 3 months of symptom onset. Septic arthritis complications: delayed diagnosis of bacterial septic arthritis allows rapid articular cartilage destruction from bacterial proteases and inflammatory cytokines — within 24-48 hours of untreated infection, irreversible joint destruction begins; outcomes include permanent joint ankylosis, osteomyelitis, systemic sepsis, and death. Chronic gout complications: recurrent gout attacks without urate-lowering therapy cause tophaceous gout (urate crystal deposits in soft tissues — tophi — around joints, tendons, external ear, and in internal organs); tophi can erode through skin and cause infection; urate nephropathy and nephrolithiasis (uric acid kidney stones) cause progressive renal impairment. Osteoarthritis complications: severe end-stage OA causes functional disability requiring joint replacement — complications of total knee and hip arthroplasty include prosthetic joint infection, deep vein thrombosis, pulmonary embolism, nerve injury, and aseptic loosening. Psychological complications: chronic joint pain causes depression (present in 30-50% of RA patients), anxiety, sleep disturbance, and social isolation. Iatrogenic complications: long-term oral NSAID use causes peptic ulceration, GI bleeding, and renal impairment; long-term corticosteroids cause osteoporosis, diabetes, hypertension, Cushing's syndrome, and adrenal suppression.

Prevention strategies vary by the underlying cause of joint pain. Osteoarthritis prevention: weight management is the most modifiable risk factor — maintaining a healthy BMI significantly reduces the mechanical load on knee and hip joints; regular low-impact exercise (swimming, cycling, walking) strengthens periarticular muscles, improving joint stability and reducing OA risk; avoid joint injury where possible (sports protective equipment, proper technique); occupational risk reduction for repetitive joint loading. Gout prevention: dietary and lifestyle modification to reduce hyperuricaemia — reduce dietary purines (limit red meat, organ meats, shellfish, fructose-sweetened drinks); limit alcohol (especially beer); increase hydration; achieve and maintain a healthy weight; avoid thiazide diuretics where feasible (alternatives with lower uricosuric effect); long-term allopurinol maintains serum urate below 360 µmol/L and prevents recurrent attacks, tophi, and renal complications — adherence is the key challenge. Septic arthritis prevention: prompt antibiotic treatment of skin infections and bacteraemia reduces risk of haematogenous joint seeding; antibiotic prophylaxis before dental procedures for patients with prosthetic joints (per orthopaedic and dental guidelines); aseptic technique for joint injections and aspiration. Inflammatory arthritis — no established primary prevention; early diagnosis and DMARD therapy prevent structural joint damage. Joint protection in inflammatory arthritis: occupational therapy for joint protection strategies, assistive devices (grab rails, raised seats, lever taps), and activity modification to reduce joint stress during inflammatory flares.

Seek emergency care immediately for: a single hot, red, swollen, exquisitely tender joint with fever, rigors, or systemic unwell feeling — this presentation must be treated as septic arthritis until proven otherwise; joint aspiration within hours is essential to prevent permanent joint destruction; do not delay assessment even if an alternative cause (gout, flare of known arthritis) seems more likely. Any prosthetic joint that is acutely painful, swollen, or discharging should be treated as an emergency — prosthetic joint infection requires urgent orthopaedic assessment and may require surgical revision. See a GP or rheumatologist promptly (within 1 week) for: symmetric small joint swelling (MCP, PIP, wrist joints) lasting more than 6 weeks — early RA is a rheumatological emergency where urgent DMARD initiation within 3 months prevents joint erosion; multiple hot, swollen joints with fever without a clear cause; joint pain with a rash on the face, scalp, or extensor surfaces; joint pain with inflammatory back pain and morning stiffness above 30 minutes in a person under 45. See a GP routinely for: joint pain lasting more than 6 weeks affecting daily function; joint pain that is unexplained, progressive, or not responding to over-the-counter analgesia; joint pain in a child (juvenile idiopathic arthritis — specialist paediatric rheumatology referral warranted); and joint pain in a person with known psoriasis or inflammatory bowel disease — screening for associated arthritis is important.