What is a common presenting symptom of hyperthyroidism?

A common presenting symptom of hyperthyroidism is weight loss. This condition is characterized by an overproduction of thyroid hormones, which accelerates metabolism. As a result, individuals often experience increased energy expenditure, leading to weight loss despite normal or even increased appetite.

Weight loss occurs because the body's metabolic rate is significantly elevated, causing a breakdown of fat stores and proteins for energy. This can also be accompanied by other symptoms, such as increased sweating, heat intolerance, and nervousness, which further highlight the body's heightened state of metabolism.

In contrast, fatigue, weight gain, and cold intolerance are generally associated with hypothyroidism, where the thyroid hormone levels are insufficient, leading to a slowed metabolism and resulting in symptoms like decreased energy, weight gain, and sensitivity to cold temperatures.