A 35-year-old woman presents with symptoms of restlessness, fatigue, and palpitations. She also complains about having an increased appetite yet losing weight. On physical examination, her pulse rate is 102 beats per minute, and her thyroid gland is diffusely enlarged. What could be the cause, and what are the next steps?
The symptoms presented, such as restlessness, palpitations, fatigue, weight loss despite increased appetite, and a diffusely enlarged thyroid gland, suggest hyperthyroidism. The most common cause of hyperthyroidism is Graves' disease. Other causes include toxic multinodular goiter or a toxic adenoma. The first step would be to confirm the diagnosis with a blood test, measuring the levels of thyroid-stimulating hormone (TSH), free thyroxine (T4), and triiodothyronine (T3). A low TSH and high T4 or T3 level would confirm hyperthyroidism. Additional tests, like the thyroid-stimulating immunoglobulin (TSI) or radioactive iodine uptake test, can help determine the cause.