Which of the following is a common presenting feature of hyperthyroidism in the elderly?

Atrial fibrillation is a common presenting feature of hyperthyroidism in the elderly due to the effects of increased thyroid hormone levels on the cardiovascular system. Hyperthyroidism tends to accelerate heart rate and can lead to dysrhythmias, with atrial fibrillation being particularly prevalent among older adults.

As the elderly often have comorbid conditions and may be more sensitive to the effects of thyroid hormones, the increased metabolic state can precipitate changes in heart rhythm. This can be attributed to both the direct effects of excess thyroid hormones on the heart and the impact of hyperthyroidism on heart rate regulation.

On the other hand, elevated TSH is typically associated with hypothyroidism rather than hyperthyroidism, as it reflects a compensatory response of the pituitary gland to low thyroid hormone levels. Thyroid enlargement can occur due to various causes, but it is not a definitive indicator of hyperthyroidism, particularly in the elderly who might present with subtle symptoms. Abnormal T3 suppression is a more complex aspect of thyroid function tests and is not a primary presenting feature in routine assessments of hyperthyroidism, especially in older populations. Thus, the presence of atrial fibrillation stands out as a key clinical manifestation that may warrant further investigation for