What are the major symptoms of Graves' disease?

Graves' disease is an autoimmune disorder that leads to hyperthyroidism, characterized by an overproduction of thyroid hormones. The major symptoms of Graves' disease primarily stem from this hyperactivity of the thyroid gland. Weight loss and rapid heartbeat are significant indicators of this condition. As metabolism accelerates due to excess thyroid hormones, patients often experience unintended weight loss despite increased appetite. Additionally, the elevated levels of thyroid hormones can result in tachycardia, which is a fast or irregular heartbeat, further highlighting the hypermetabolic state induced by the disease.

Understanding the other symptoms associated with the other choices provides context as to why they are not indicative of Graves' disease. Weight gain and cold intolerance are commonly associated with hypothyroidism rather than hyperthyroidism. Fatigue and depressive symptoms can occur in various conditions, including depression or anxiety, but they aren't specific to Graves' disease. Joint pain and muscle weakness are not typical of Graves' disease; while muscle weakness can occur in some cases of hyperthyroidism, it is not as prominent or characteristic as the weight loss and rapid heartbeat observed in this disorder. Therefore, the selection of weight loss and rapid heartbeat accurately reflects the hallmark symptoms of Graves' disease.