What is the most common presentation of hyperthyroidism?

The most common presentation of hyperthyroidism is Graves' disease, which accounts for approximately 60-80% of cases. This autoimmune disorder occurs when the body produces antibodies that stimulate the thyroid, leading to an overproduction of thyroid hormones. This excessive hormone production results in the classic symptoms of hyperthyroidism, including weight loss, increased appetite, heat intolerance, anxiety, tremors, and palpitations. Additionally, Graves' disease can lead to characteristic signs such as goiter and exophthalmos (protrusion of the eyes).

Other options represent conditions related to thyroid dysfunction but are not the most common presentations of hyperthyroidism. Hashimoto's thyroiditis, for instance, typically leads to hypothyroidism due to autoimmune destruction of the thyroid gland. Thyroid storm is a severe and life-threatening exacerbation of hyperthyroidism, but it is a rare acute condition rather than a common presentation. Subacute thyroiditis, often following a viral infection, can cause temporary hyperthyroid symptoms but is also not the primary cause of hyperthyroidism. Therefore, Graves' disease is indeed the most significant and prevalent form of hyperthyroidism encountered in clinical practice.