A 36-year-old woman presents with complaints of palpitations, tremors, and a weight loss. She mentions that she has been feeling "hot" all the time and has an increased appetite. On physical examination, her pulse rate is 108 beats per minute, and her thyroid gland is diffusely enlarged. What could be the cause, and what are the next steps?
The symptoms of palpitations, tremors, weight loss, heat intolerance, increased appetite, tachycardia, and a diffusely enlarged thyroid gland are suggestive of hyperthyroidism. Graves' disease is the most common cause of hyperthyroidism. The first step is to confirm the diagnosis with blood tests, including TSH, free T4, and free T3 levels. If these indicate hyperthyroidism, additional tests such as a radioactive iodine uptake test or thyroid autoantibodies may be performed to determine the exact cause.