A 45-year-old woman presents with a history of progressive w…

A 45-year-old woman presents with a history of progressive weakness, fatigue, weight loss, nausea, and increased skin pigmentation (especially of creases, pressure areas, and nipples). Her blood pressure is 120/78 mm Hg when supine and 105/52 mm Hg when standing. Laboratory findings reveal a serum sodium of 120 mEq/L (normal is 135 to 145 mEq/L), a potassium level of 5.9 mEq/L (normal is 3.5 to 5 mEq/L), and low plasma cortisol and high ACTH levels. What diagnosis would this woman’s clinical features and laboratory findings suggest? Would her diagnosis be classified as a primary or secondary endocrine disorder? What is the significance of her darkened skin? What type of treatment would be indicated?

“I understand why I need to take this antithyroid drug,” say…

“I understand why I need to take this antithyroid drug,” says Mr. Henderson, who has newly diagnosed hyperthyroidism. “It stops my thyroid gland from making any more thyroid hormones. But why does it take several weeks to have full effects? Don’t we make thyroid hormones every day?”

A 25-year-old woman presents with a complaint of rapid weigh…

A 25-year-old woman presents with a complaint of rapid weight loss despite a voracious appetite. Physical examination reveals tachycardia (pulse rate 110 bpm at rest), fine moist skin, a symmetrically enlarged thyroid, mild bilateral quadriceps muscle weakness, and fine tremor. These findings strongly suggest hyperthyroidism. What laboratory tests should be ordered, and what results should be anticipated?