Hyperthyroidism may be Subtle or Atypical in the Elderly

Nariman Malik, BSc

Hyperthyroidism is defined as an excess of circulating thyroid hormones, either thyroxine (T4) or triiodothyronine (T3).1 In Canada, its prevalence is approximately 1.9% and it is ten times more common in women than in men.2 The disease can present at any age but is less common before the age of 15.3

Hyperthyroidism is an important cause of morbidity in the elderly. The clinical manifestations of hyperthyroidism vary from one patient to another and no single clinical manifestation is a specific indicator of the condition. Hyperthyroidism classically presents with symptoms that affect almost every organ system.3 The typical features include: weight loss with preserved appetite, heat intolerance, nervousness, anxiety, insomnia, proximal muscle weakness, fatigue, tremor, heart palpitations, and increased frequency of bowel movements. Other general signs include hyperactivity, tachycardia, atrial fibrillation, systolic hypertension, hyperreflexia, lid lag, and eyelid retraction.

Elderly persons may present with these classic symptoms or more usually, their presentation is atypical (please refer to table 1).