Hypertension or high blood pressure is a major cause of illness and death in the United States today.1,2 An estimated thirty-six million people suffer from this disease.3 Prolonged hypertension and its attendant strain on various organs may cause heart failure, brain stroke or kidney damage.4 Usually, a pressure of 140/90 mm Hg is taken to be the dividing line between normotension and hypertension.5,6
The hypertensive condition is generally characterized as either primary (essential) hypertension or secondary hypertension.1 A specific cause can be identified in secondary hypertensive patients, such as, pheochromocytoma or adrenal tumor. These causes can typically be corrected by surgery. Essential hypertension occurs in about 90% of the hypertensive population. The etiology of essential hypertension is unknown.1,3,6 The increase in diastolic pressure in primary hypertension may take on either a gradual (benign) or accelerated (malignant) course. The prognosis of gradual hypertension is more favorable than that of the accelerated. Blood pressure in the essential hypertensive patient can almost always be controlled by drug therapy.
It is currently accepted that in most hypertensive cases the primary abnormality is due to a high peripheral resistance.7 Numerous biological feedback mechanisms interact in trying to return the body to the normotensive state.8 Some factors involved in the maintenance of homeostasis are central and peripheral sympathetic activity, renal pressor and depressor mechanisms, antidiuretic hormone, sodium balance, baroreceptors, small blood vessel resistance, blood volume and viscosity.1,4,7
| Identifer | oai:union.ndltd.org:vcu.edu/oai:scholarscompass.vcu.edu:etd-6226 |
| Date | 01 January 1982 |
| Creators | Lund, Mary Quinn |
| Publisher | VCU Scholars Compass |
| Source Sets | Virginia Commonwealth University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
| Rights | © The Author |
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