What is a classic symptom of Graves' disease?

Graves' disease is an autoimmune disorder that leads to overactivity of the thyroid gland, resulting in hyperthyroidism. A classic symptom associated with Graves' disease is exophthalmos, which refers to the protrusion of the eyes. This condition occurs due to the accumulation of glycosaminoglycans in the retro-orbital space, causing swelling and pushing the eyes forward.

This symptom is quite distinctive and helps differentiate Graves' disease from other forms of hyperthyroidism and thyroid dysfunction. While other symptoms of hyperthyroidism can include weight loss, increased appetite, heat intolerance, and nervousness, exophthalmos is particularly characteristic of Graves' due to the underlying autoimmune process affecting the eyes and surrounding tissues.

In contrast, the other options do not align with the typical presentation of Graves' disease. Weight gain and fatigue are not typical of hyperthyroidism, which generally leads to weight loss and increased energy levels. Hypoglycemia is not a direct symptom of Graves' disease; rather, it is often related to insulin or metabolic issues. Joint pain may occur in various conditions but is not a hallmark symptom of Graves' disease.