Which condition indicates an overactive thyroid (hyperthyroidism)?

Graves' disease is a common autoimmune disorder that leads to hyperthyroidism, which is characterized by an overproduction of thyroid hormones. This results in various symptoms such as increased metabolism, weight loss, heat intolerance, and anxiety, among others.

In the case of Graves' disease, the body's immune system mistakenly attacks the thyroid, causing it to become enlarged and produce excessive amounts of thyroid hormones. This elevated level of hormones stimulates the body's metabolism and the associated symptoms of hyperthyroidism.

Other conditions listed may affect thyroid function but do not specifically indicate hyperthyroidism. For example, Hashimoto's thyroiditis typically leads to hypothyroidism, where the thyroid does not produce enough hormones. Thyroid carcinoma involves cancer of the thyroid, which may alter hormone production but is not directly indicative of hyperthyroidism. A pituitary adenoma can influence thyroid function indirectly through overproduction of thyroid-stimulating hormone (TSH), yet it does not specifically indicate an overactive thyroid without further context.

Therefore, the presence of Graves' disease is the most direct indicator of hyperthyroidism among the options given.