Thyroid diseases that can affect blood pressure
What are three primary diseases of the thyroid that can affect blood pressure?
• Hypothyroidism is the most common thyroid disease that is associated with hypertension (3% of newly diagnosed hypertensives), although the mechanism is unclear. After appropriate thyroid replacement, blood pressure typically falls without specific antihypertensive therapy. Because hypothyroidism is a rare cause of secondary hypertension, a serum-ultrasensitive thyroid-stimulating hormone was not generally recommended as an initial test for all patients newly diagnosed with hypertension until the 2017 American College of Cardiology/American Heart Association hypertension guidelines (although other historical and physical findings might justify it).
• Hyperthyroidism typically presents in younger patients with tachycardia, hypertension, a wide pulse pressure, and other traditional signs, but older people sometimes lack one or more of these typical features. The now-standard initial test is a serum-ultrasensitive thyroid-stimulating hormone level. Therapy is usually propranolol, which treats the hypertension, tachycardia, and (at least according to traditional pharmacologic teachings, now widely challenged) inhibits the peripheral conversion of thyroxine (T 4 ) to triiodothyronine (T 3 ).