A 25-year-old woman comes into your office with a three-month history of weight loss, irritability, insomnia, and palpitations. Her past medical history is insignificant. She is not taking any current medications and denies drug abuse. Her blood pressure is 155/70 mmHg and heart rate is 110/min. Physical examination reveals lid retraction, fine tremor of the hands, and increased neck circumference. The most probable cause of hypertension in this patient is: A. Hyperdynamic circulation B. Increased peripheral vascular resistance C. Sodium retention D. Decreased vascular compliance E. Increased intravascular volume
Hyperthyroidism usually causes systolic hypertension; where as, hypothyroidism causes diastolic hypertension. In this case, classical clinical presentation of hyperthyroidism is described (weight loss, irritability, tachycardia, tremor, lid retraction). It is important to know that hyperthyroidism may cause secondary hypertension due to hyperdynamic state. Excess thyroid hormone increases target organ susceptibility to beta-adrenergic receptor stimulation causing tachycardia and increased cardiac contractility. Widened pulse pressure reflects hyperdynamic state. In extreme cases, high output heart failure may develop. Peripheral resistance is not increased (Choice B). Sodium retention (Choice C) and increased intravascular volume (Choice E) are more characteristic for renal hypertension. Decreased vascular compliance (Choice D) causes isolated systolic hypertension with widened pulse pressure in elderly patients
