Joint Pain

Joint pain (arthralgia) is pain felt in one or more joints. The clinical question is whether it represents inflammatory disease (rheumatoid arthritis, gout, lupus, psoriatic arthritis), mechanical disease (osteoarthritis, overuse), metabolic disease (vitamin D deficiency, hypothyroidism) or referred pain from elsewhere. Time course matters a lot — sudden severe pain in one joint suggests gout, septic arthritis or fracture; chronic symmetric pain in small joints suggests rheumatoid arthritis; deep stiffness in large weight-bearing joints suggests osteoarthritis.

• Gout — sudden severe attack, classically the big toe.
• Osteoarthritis — gradual onset, weight-bearing joints, worse at end of day.
• Rheumatoid arthritis — symmetric small-joint pain with morning stiffness lasting >1 hour.
• Psoriatic arthritis — joint pain with skin or nail psoriasis.
• Vitamin D deficiency — generalised musculoskeletal aching.
• Hypothyroidism — diffuse joint and muscle pain.
• Lyme disease, viral arthritis — sometimes follows specific exposures.

A focused work-up starts with: uric acid, CRP, ESR, rheumatoid factor, anti-CCP, ANA, vitamin D, TSH. The specific panel depends on the clinical picture — chronic symmetric small-joint pain leans toward RA testing; sudden single big-toe pain leans toward uric acid and joint aspiration; non-specific musculoskeletal aching leans toward vitamin D and thyroid.