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High Blood Pressure

High blood pressure is a medical condition where the blood pressure is chronically elevated. Persistent high blood pressure is one of the risk factors for strokes, heart attacks and heart failure, and is a leading cause of chronic renal failure. Often, physical symptoms of high blood pressure in basic hypertension are not pressent and discovered by healthcare professionals prior to any symptoms being noticed during a regular checkup.

Blood pressure is a continuous variable, and risks of various adverse outcomes rise with it. Hypertension is usually diagnosed on finding blood pressure above 140/90 mmHg measured on both arms on three occasions over a few weeks. Recently, the JNC VII (The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure) has defined blood pressure over 120/80 mmHg and below 140/90 mmHg as "pre-high blood pressure". "Pre-high blood pressure is not a disease category. Rather, it is a designation chosen to identify individuals at high risk of developing high blood pressure (JNC VII)." Normal blood pressure is 120/80 mmHg.

In patients with diabetes mellitus or kidney disease studies have shown that blood pressure over 130/80 mmHg should be considered a risk factor and may warrant treatment.

high blood pressure symptoms

Hypertension is usually found incidentally - "case finding" by healthcare professionals. It normally produces no physical symptoms of high blood pressure.

Malignant symptoms of high blood pressure (or accelerated high blood pressure) is distinct as a late phase in the condition, and may present with:

  • headaches
  • blurred vision
  • end-organ damage

It is recognized that stressful situations can increase the blood pressure (and thus high blood pressure symptoms); if a normally normotensive patient has a high blood pressure only when being reviewed by a health care professional, this is colloquially termed white coat effect. Since most of what we know of high blood pressure and its outcome with or without modification is based on large series of readings in doctors' offices and clinics (eg Framingham) it is difficult to be sure of the significance of white-coat high blood pressure. Ambulatory monitoring may help determine whether traffic and ticket inspectors produce similar sustained rises.

Hypertension is often confused with mental tension, stress and anxiety. While chronic anxiety is associated with poor outcomes in people with high blood pressure, it alone does not cause it.

possible causes of high blood pressure (essential)

  • Age. Over time, the number of collagen fibers in artery and arteriole walls increases, making blood vessels stiffer. With the reduced elasticity comes a smaller cross-sectional area in systole, and so a raised mean arterial blood pressure.
  • High salt intake
  • Sedentary lifestyle
  • Tobacco smoking
  • Alcohol abuse
  • High levels of saturated fat in the diet
  • Obesity. In obese subjects, losing a pound in weight generally reduces blood pressure by 1mmHg.
  • Stress
  • Low birth-weight
  • Diabetes mellitus
  • Various genetic causes

possible causes of high blood pressure (inessential)

  • Pregnancy.
  • Kidney disease or renal artery stenosis
  • Certain cancers
  • Drugs. In particular, alcohol, nasal decongestants with adrenergic effects, NSAIDs, MAOIs, adrenoceptor stimulants, and the contraceptive pill (ethinyl-estradiol) can cause high blood pressure while in use.
  • Malformed aorta
  • Slow pulse
  • Anemia
  • Fever
  • Aortic valve disease

Posted by Staff at June 2, 2005 6:20 AM

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