Hypertension is classified as either pri-mary hypertension or secondary hyper-tension; about 9095% of cases are cate-gorized as "primary hypertension" which means high blood pressure with no obvi-ous underlying medical cause. Hyperten-sion is a major risk factor for stroke, myo-
cardial infarction (heart attacks), heart failure, aneurysms of the arteries (e.g. aortic aneurysm), peripheral arterial dis-ease and is a cause of chronic kidney dis-ease. Hypertension is rarely accompa-nied by any symptoms
Hypertension (HTN) is a chronic medical condition in which the blood pressure in the arteries is elevated. Normal blood pressure at rest is within the range of 100-140mmHg systolic (top reading) and 60-90mmHg diastolic (bottom reading). High blood pressure is said to be present if it is persistently at or above 140/90 mmHg.
In people aged 18 years or older hyper-tension is defined as a systolic and/or a diastolic blood pressure measurement consistently higher than an accepted nor-mal value (currently 139 mmHg systolic, 89 mmHg diastolic. Lower thresholds are used (135 mmHg systolic or 85 mmHg diastolic) if measurements are derived from 24-hour ambulatory or home monitoring. Recent international hypertension guidelines have also cre-ated categories below the hypertensive range to indicate a continuum of risk with higher blood pressures in the nor-
mal range. JNC7 (2003) uses the term prehypertension for blood pressure in the range 120-139 mmHg systolic and/or 80-89 mmHg diastolic. Hypertension is also sub-classified: JNC7 distinguishes hypertension stage I, hypertension stage II, and isolated systolic hypertension. Iso-lated systolic hypertension refers to ele-vated systolic pressure with normal dia-stolic pressure and is common in the eld-erly. Hypertension is classified as "resis-tant" if medications do not reduce blood pressure to normal levels.
BLOOD PRESSURE CLASSIFICATION
SISTOLIC BLOOD PRESSURE
DIASTOLIC BLOOD PRESSURE
Normal < 120 mmHg < 80 mmHg
Prehypertension 120 - 139 mmHg 80 -89 mmHg
Stage 1 Hypertension 140 - 159 mmHg 90 - 99 mmHg
Stage 2 Hypertension 180 mmHg 100 mmHg
Uncontrolled high blood pressure can lead to:
Heart attack or stroke. High blood pressure can cause hardening and thickening of the arteries (atherosclero-sis), which can lead to a heart attack, stroke or other complications.
Aneurysm. Increased blood pres-sure can cause your blood vessels to weaken and bulge, forming an aneu-rysm. If an aneurysm ruptures, it can be life-threatening.
Heart failure. To pump blood against the higher pressure in your ves-sels, your heart muscle thickens. Eventu-ally, the thickened muscle may have a hard time pumping enough blood to meet your body's needs, which can lead to heart failure.
Weakened and narrowed blood vessels in your kidneys. This can prevent these organs from function-ing normally.
Thickened, narrowed or torn blood vessels in the eyes. This can re-sult in vision loss.
Metabolic syndrome. This syn-drome is a cluster of disorders of your body's metabolism including in-creased waist circumference, high triglyc-erides, low high-density lipoprotein (HDL), or "good," cholesterol, high blood pressure, and high insulin levels. If you have high blood pressure, you're more likely to have other components of metabolic syndrome. The more compo-nents you have, the greater your risk of developing diabetes, heart disease or stroke.