Secondary hypertension (or, less commonly, inessential hypertension) is a type of
hypertension which by definition is caused by an identifiable underlying primary cause. It is much less common than the other type, called
essential hypertension, affecting only 5-10% of hypertensive patients. It has many different causes including
endocrine diseases,
kidney diseases, and
tumors. It also can be a
side effect of many
medications.
Types
Kidney
Renovascular hypertension
It has two main causes: fibromuscular dysplasia and atherosclerosis of the renal artery resulting in stenosis.[citation needed]
Here, however, increased CO cannot solve the structural problems causing renal artery hypotension, with the result that CO remains chronically elevated.[citation needed]
Neurogenic hypertension – excessive secretion of norepinephrine and epinephrine which promotes
vasoconstriction resulting from chronic high activity of the
sympathoadrenal system, the
sympathetic nervous system and the
adrenal gland. The specific mechanism involved is increased release of the "stress hormones",
epinephrine (adrenaline) and
norepinephrine which increase blood output from the heart and constrict arteries. People with neurogenic hypertension respond poorly to treatment with diuretics as the underlying cause of their hypertension is not addressed.[13]
Pheochromocytoma – a tumor which results in an excessive secretion of norepinephrine and epinephrine which promotes vasoconstriction
A variety of adrenal cortical abnormalities can cause hypertension, In primary
aldosteronism there is a clear relationship between the aldosterone-induced sodium retention and the hypertension.[14]
Congenital adrenal hyperplasia, a group of autosomal recessive disorders of the enzymes responsible for steroid hormone production, can lead to secondary hypertension by creating atypically high levels of
mineralocorticoid steroid hormones. These mineralocorticoids cross-react with the aldosterone receptor, activating it and raising blood pressure.[citation needed]
17 alpha-hydroxylase deficiency causes an inability to produce cortisol. Instead, extremely high levels of the precursor hormone corticosterone are produced, some of which is converted to
11-Deoxycorticosterone (DOC), a potent mineralocorticoid not normally clinically important in humans. DOC has blood-pressure raising effects similar to aldosterone, and abnormally high levels result in
hypokalemic hypertension.[15]
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.
White coat hypertension: elevated blood pressure in a clinical setting but not in other settings, probably due to the anxiety some people experience during a clinic visit.
Perioperative hypertension is development of hypertension just before, during or after
surgery. It may occur before surgery during the induction of
anesthesia; intraoperatively e.g. by pain-induced
sympathetic nervous system stimulation; in the early postanesthesia period, e.g. by pain-induced sympathetic stimulation,
hypothermia,
hypoxia, or
hypervolemia from excessive intraoperative fluid therapy; and in the 24 to 48 hours after the postoperative period as fluid is mobilized from the extravascular space. In addition, hypertension may develop perioperatively because of discontinuation of long-term antihypertensive medication.[40]
Medication side effects
Certain medications, including
NSAIDs (
ibuprofen/Motrin) and steroids can cause hypertension.[41][42][43][44][45] Other medications include estrogens (such as those found in oral contraceptives with high estrogenic activity), certain antidepressants (such as
venlafaxine),
buspirone,
carbamazepine,
bromocriptine,
clozapine, and
cyclosporine.[39]
High blood pressure that is associated with the sudden
withdrawal of various
antihypertensive medications is called rebound hypertension.[46][47][48][49][50][51][52] The increases in blood pressure may result in blood pressures greater than when the medication was initiated. Depending on the severity of the increase in blood pressure, rebound hypertension may result in a
hypertensive emergency. Rebound hypertension is avoided by gradually reducing the dose (also known as "dose tapering"), thereby giving the body enough time to adjust to reduction in dose. Medications commonly associated with rebound hypertension include centrally-acting antihypertensive agents, such as
clonidine[53] and methyl-dopa.[52]
Other herbal or "natural products" which have been associated with hypertension include
Ephedra,
St John's wort, and licorice.[39]
Pregnancy
Few women of childbearing age have high blood pressure, up to 11% develop
hypertension of pregnancy.[54] While generally benign, it may herald three complications of pregnancy:
pre-eclampsia,
HELLP syndrome and
eclampsia. Follow-up and control with medication is therefore often necessary.[55][56]
Because of the ubiquity of arsenic in ground water supplies and its effect on cardiovascular health, low dose
arsenic poisoning should be inferred as a part of the pathogenesis of idiopathic hypertension. Idiopathic and essential are both somewhat synonymous with primary hypertension. Arsenic exposure has also many of the same signs of primary hypertension such as
headache,
somnolence,[60]confusion,
proteinuria,[61]visual disturbances, and
nausea and
vomiting.[62]
Potassium deficiency
Due to the role of intracellular potassium in regulation of cellular pressures related to sodium, establishing potassium balance has been shown to reverse hypertension.
[63]
Diagnosis
The ABCDE mnemonic can be used to help determine a secondary cause of hypertension.
A: Accuracy, Apnea, Aldosteronism
B: Bruits, Bad Kidney
C: Catecholamines, Coarctation of the Aorta, Cushing's Syndrome
^Méndez GP, Klock C, Nosé V (December 2008). "Juxtaglomerular Cell Tumor of the Kidney: Case Report and Differential Diagnosis With Emphasis on Pathologic and Cytopathologic Features". Int. J. Surg. Pathol. 19 (1): 93–98.
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^Ziaja J, Cholewa K, Mazurek U, Cierpka L (2008). "[Molecular basics of aldosterone and cortisol synthesis in normal adrenals and adrenocortical adenomas]". Endokrynologia Polska (in Polish). 59 (4): 330–39.
PMID18777504.
^Astegiano M, Bresso F, Demarchi B, et al. (March 2005). "Association between Crohn's disease and Conn's syndrome. A report of two cases". Panminerva Medica. 47 (1): 61–4.
PMID15985978.
^Yudofsky, Stuart C.; Robert E. Hales (2007). The American Psychiatric Publishing Textbook of Neuropsychiatry and Behavioral Neurosciences (5th ed.). American Psychiatric Pub, Inc.
ISBN978-1-58562-239-9.
^Salerno, SM; Jackson, JL; Berbano, EP (8–22 August 2005). "Effect of oral pseudoephedrine on blood pressure and heart rate: a meta-analysis". Archives of Internal Medicine. 165 (15): 1686–94.
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^atsdr-medical management guidelines for arsenic trioxide
^Arsenic Author: Frances M Dyro, MD, Chief of the Neuromuscular Section, Associate Professor, Department of Neurology, New York Medical College, Westchester Medical Center