Subclinical hypothyroidism causing hypertension in pregnancy.

This is a case of a 25-year-old primigravida who was referred to the hypertension specialist for elevated blood pressures. The patient had an elevated thyroid-stimulating hormone with normal free thyroxine (T4) levels and was positive for thyroid peroxidase antibodies resulting in a diagnosis of subclinical hypothyroidism. The patient was successfully treated with levothyroxine which normalized the blood pressure without the need for antihypertensive treatment. This case illustrates a cause of secondary hypertension that is not always considered in the differential diagnosis of a patient with hypertension in pregnancy.