Carpal tunnel syndrome and median nerve compression

Rheumatoid arthritis is a chronic systemic autoimmune disease causing symmetric small-joint polyarthritis of the hands and feet that spares the distal interphalangeal joints, with morning stiffness over an hour. Diagnosis combines the ACR/EULAR classification criteria with rheumatoid factor, anti-CCP antibody, and radiographs. Treat-to-target management anchors on methotrexate, escalating to a biologic or targeted synthetic disease-modifying antirheumatic drug when remission is not reached.

Hypothyroidism is thyroid hormone deficiency, most commonly caused by autoimmune (Hashimoto) thyroid failure in iodine-sufficient countries, diagnosed by an elevated thyroid-stimulating hormone with a low or normal free thyroxine. First-line treatment is levothyroxine dosed at 1.6 mcg/kg lean body weight orally once daily, titrated using thyroid-stimulating hormone rechecked no sooner than 6 weeks after any dose change.

Acromegaly is acral and soft-tissue overgrowth from chronic growth hormone excess, almost always caused by a GH-secreting pituitary adenoma, diagnosed with an elevated IGF-1 confirmed by failure of GH suppression on an oral glucose tolerance test. First-line treatment is transsphenoidal resection of the pituitary tumor, with somatostatin analogues, pegvisomant, or cabergoline for persistent disease.

Amyloidosis is extracellular deposition of misfolded protein fibrils that stain apple-green with Congo red under polarized light, most often AL (clonal light chains, linked to plasma cell dyscrasias), AA (chronic inflammation), or ATTR (transthyretin, hereditary or wild-type). Diagnosis requires tissue biopsy for Congo red birefringence plus typing of the amyloid protein, and treatment targets the underlying source, plasma-cell-directed therapy for AL, inflammatory disease control for AA, and transthyretin stabilizers or silencers for ATTR.

Diabetic neuropathy is length-dependent nerve damage from chronic hyperglycemia, most often a distal symmetric sensorimotor polyneuropathy causing numbness, pain, and loss of ankle reflexes, with autonomic, mononeuropathy, and radiculoplexus variants. Diagnosis is clinical after excluding other causes; management is tight glycemic control plus gabapentinoid or duloxetine therapy for painful symptoms.

De Quervain tendinopathy is noninflammatory thickening of the abductor pollicis longus and extensor pollicis brevis tendons at the first dorsal wrist compartment, diagnosed clinically by radial wrist pain reproduced on the Finkelstein test. First-line care is rest, NSAIDs, and thumb spica splinting, escalating to corticosteroid injection and then surgical release for refractory cases.

A ganglion cyst is a mucin-filled swelling that herniates from a joint capsule or tendon sheath, most often on the dorsal wrist, diagnosed clinically by transillumination and managed with observation, aspiration with corticosteroid injection, or surgical excision for persistent or symptomatic cysts.

Fibromyalgia is a chronic centralized pain syndrome causing widespread musculoskeletal pain with nonrestorative sleep, fatigue, and cognitive difficulty, driven by central sensitization rather than peripheral inflammation or structural damage. It is a positive clinical diagnosis made with the widespread pain index and symptom severity scale, not a diagnosis of exclusion. First-line treatment is patient education plus a graded aerobic exercise program, with duloxetine, milnacipran, or pregabalin as adjunctive pharmacotherapy.