Secondary hypertension

Overview
While most forms of hypertension are not known a underlying cause (and are thus known as "essential hypertension" or "primary hypertension"), in about 10% of the cases, there is a known cause, and thus the hypertension is secondary hypertension (or, less commonly, inessential hypertension).

Renovascular hypertension (I15.0)

 * See main article at Renovascular hypertension.

Hypertension secondary to other renal disorders (I15.1)

 * Chronic renal failure
 * Kidney disease / renal artery stenosis: the normal physiological response to low blood pressure in the renal arteries is to increase cardiac output (CO) to maintain the pressure needed for glomerular filtration. Here, however, increased CO cannot solve the structural problems causing renal artery hypotension, with the result that CO remains chronically elevated.

Hypertension secondary to endocrine disorders (I15.2)

 * Pheochromocytoma
 * Hyperaldosteronism (Conn's syndrome)
 * Cushing's disease
 * Hyperparathyroidism
 * Acromegaly
 * Hyperthyroidism
 * Hypothyroidism

Other secondary hypertension (I15.8)

 * Obstructive sleep apnea
 * Liquorice (when consumed in excessive amounts)
 * Scleroderma
 * Neurofibromatosis
 * Pregnancy: unclear etiology.
 * Cancers: tumours in the kidney can operate in the same way as kidney disease. More commonly, however, tumors cause inessential hypertension by ectopic secretion of hormones involved in normal physiological control of blood pressure.
 * Drugs: In particular, alcohol, nasal decongestants with adrenergic effects, NSAIDs, MAOIs, adrenoceptor stimulants, and combined methods of hormonal contraception (those containing ethinyl-estradiol) can cause hypertension while in use.
 * Heavy alcohol use
 * Steroid use
 * Malformed aorta, slow pulse: these cause reduced blood flow to the renal arteries, with physiological responses as already outlined.
 * Aortic valve disease: unclear etiology.
 * Coarcation of the aorta
 * Anemia: unclear etiology.
 * Fever: unclear etiology.