This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
A 30-year-old female complains of palpitations, fatigue, and insomnia. On physical exam, her extremities are warm and she is tachycardic. There is diffuse thyroid gland enlargement and proptosis. There is a thickening of the skin in the pretibial area. Which of the following lab values would you expect in this patient? 
Select and explain. 
A. Increased TSH, total thyroxine, total T3, B. Decreased TSH, increased total thyroxine, C. Increased T3 uptake, decreased T3, D. Decreased TSH, normal T4
B: Decreased TSH, increased total thyroxine
Answer: B: Decreased TSH, increased total thyroxine 
Explanation: (b) Source: (Braunwald, 15/e, pp 2069-2074.) This patient has clinical symptoms of thyrotoxicosis. Most patients with thyrotoxicosis have increases in total and free concentrations of T3 and T4. (Some may have isolated T3 or T4 increases.) Most thyrotoxicosis results in suppression of pituitary TSH secretion, so low TSH levels can also confirm the diagnosis.