Subclinical Hyperthyroidism in the Elderly: Small Numbers, Big Consequences

Subclinical hyperthyroidism (SCHyper), defined by suppressed serum thyroid-stimulating hormone (TSH) with normal free thyroxine and triiodothyronine, represents a frequently underrecognized condition that disproportionately burdens the elderly population.With a prevalence reaching up to 15.4% in individuals aged 75 years and above, its clinical footprint in geriatric medicine is substantial yet underappreciated. 1 e diagnostic challenge in older adults is compounded by the condition's insidious nature.Classical hyperthyroid symptoms -palpitations, tremor, heat intolerance, and anxiety -are frequently absent, misattributed to comorbidities, or masked by age-related physiological changes.Consequently, diagnosis relies on biochemical vigilance rather than symptom recognition.Crucially, a single suppressed TSH is insufficient for diagnosis; confirmation requires repeat testing after three to six months, with earlier reassessment -within two to four weeks -warranted in those with atrial fibrillation or established cardiac disease. 2 Before confirming the diagnosis, common causes of transient TSH suppression must be excluded -including non-thyroidal illness, medications such as dopamine, glucocorticoids, amiodarone, or immune checkpoint inhibitors, and destructive thyroiditis.Unlike true SCHyper, these conditions typically show free T4 and T3 in the lower reference range, with TSH normalizing once the underlying cause resolves.2,