Secondary hypertension—can be explained by a specific disease. (3 then drugs):
i. Renal disorders
—most common cause; for instance, renal artery stenosis causes reduced renal perfusion & activation of the renin-angiotensin-aldosterone system.
- ii. Endocrine disorders (these are examples—not an exhaustive list)—
- a. Adrenocortical hormone excess (both mineralocorticoids & glucocorticoids)
- 1. Steroid hormones are synthesized from cholesterol.
- b. Pheochromocytoma (rare, but obvious)-tumor of the adrenal gland that causes too
- much release of epinephrine and norepinephrine
- c. Acromegaly
- d. Hypo- or hyper-thyroidism
- iii. Vascular disorders—
- a. Arteriosclerosis—increases systemic vascular resistance, therefore blood pressure; also narrows renal arteries as in #1 above
- b. Coarctation of the aorta—markedly elevated BP in arms, low BP in legs
- c. Neurologic disorders—elevated intracranial pressure, spinal cord injuries can cause autonomic hyperreflexia
—amphetamines, steroids, oral contraceptives, caffeine, nicotine, cocaine, etc.