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High blood pressure (HBP) or hypertension means high pressure (tension) in the arteries. Arteries are vessels that carry blood from the pumping heart to all the tissues and organs of the body. High blood pressure does not mean excessive emotional tension, although emotional tension and stress can temporarily increase blood pressure. Normal blood pressure is below 120/80; blood pressure between 120/80 and 139/89 is called "pre-hypertension", and a blood pressure of 140/90 or above is considered high.

Complications of Hypertension

The excessive pressure on your artery walls caused by high blood pressure can damage your blood vessels, as well as organs in your body. The higher your blood pressure and the longer it goes uncontrolled, the greater the damage.

Uncontrolled high blood pressure can lead to:

  • Heart attack or stroke. High blood pressure can cause hardening and thickening of the arteries (atherosclerosis), which can lead to a heart attack, stroke or other complications.
  • Aneurysm. Increased blood pressure can cause your blood vessels to weaken and bulge, forming an aneurysm. If an aneurysm ruptures, it can be life-threatening.
  • Heart failure. To pump blood against the higher pressure in your vessels, your heart muscle thickens. Eventually, 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 functioning normally.
  • Thickened, narrowed or torn blood vessels in the eyes. This can result in vision loss.
  • Metabolic syndrome. This syndrome is a cluster of disorders of your body's metabolism — including increased waist circumference, high triglycerides, 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 components you have, the greater your risk of developing diabetes, heart disease or stroke.
  • Trouble with memory or understanding. Uncontrolled high blood pressure also may affect your ability to think, remember and learn. Trouble with memory or understanding concepts is more common in people who have high blood pressure.

Causes of Hypertension

Two forms of high blood pressure have been described: essential (or primary) hypertension and secondary hypertension. Essential hypertension is a far more common condition and accounts for 95% of hypertension. The cause of essential hypertension is multifactorial, that is, there are several factors whose combined effects produce hypertension. In secondary hypertension, which accounts for 5% of hypertension, the high blood pressure is secondary to (caused by) a specific abnormality in one of the organs or systems of the body. Essential hypertension affects approximately 72 million Americans, yet its basic causes or underlying defects are not always known. Nevertheless, certain associations have been recognized in people with essential hypertension. For example, essential hypertension develops only in groups or societies that have a fairly high intake of salt, exceeding 5.8 grams daily. Salt intake may be a particularly important factor in relation to essential hypertension in several situations, and excess salt may be involved in the hypertension that is associated with advancing age, African American background, obesity, hereditary (genetic) susceptibility, and kidney failure (renal insufficiency). The Institute of Medicine of the National Academies recommends healthy 19 to 50-year-old adults consume only 3.8 grams of salt to replace the average amount lost daily through perspiration and to achieve a diet that provides sufficient amounts of other essential nutrients. Genetic factors are thought to play a prominent role in the development of essential hypertension. However, the genes for hypertension have not yet been identified. (Genes are tiny portions of chromosomes that produce the proteins that determine the characteristics of individuals.) The current research in this area is focused on the genetic factors that affect the renin-angiotensin-aldosterone system. This system helps to regulate blood pressure by controlling salt balance and the tone (state of elasticity) of the arteries.Approximately 30% of cases of essential hypertension are attributable to genetic factors. For example, in the United States, the incidence of high blood pressure is greater among African Americans than among Caucasians or Asians. Also, in individuals who have one or two parents with hypertension, high blood pressure is twice as common as in the general population. Rarely, certain unusual genetic disorders affecting the hormones of the adrenal glands may lead to hypertension. The vast majority of patients with essential hypertension have in common a particular abnormality of the arteries: an increased resistance (stiffness or lack of elasticity) in the tiny arteries that are most distant from the heart (peripheral arteries or arterioles). The arterioles supply oxygen-containing blood and nutrients to all of the tissues of the body. The arterioles are connected by capillaries in the tissues to the veins (the venous system), which returns the blood to the heart and lungs. Just what makes the peripheral arteries become stiff is not known. Yet, this increased peripheral arteriolar stiffness is present in those individuals whose essential hypertension is associated with genetic factors, obesity, lack of exercise, overuse of salt, and aging. Inflammation also may play a role in hypertension since a predictor of the development of hypertension is the presence of an elevated C reactive protein level (a blood test marker of inflammation) in some individuals.

Signs & Symptoms of Hypertension

Uncomplicated high blood pressure usually occurs without any symptoms (silently) and so hypertension has been labeled "the silent killer." It is called this because the disease can progress to finally develop any one or more of the several potentially fatal complications of hypertension such as heart attacks or strokes. Uncomplicated hypertension may be present and remain unnoticed for many years, or even decades. This happens when there are no symptoms, and those affected fail to undergo periodic blood pressure screening. Some people with uncomplicated hypertension, however, may experience symptoms such as headache, dizziness, shortness of breath, and blurred vision. The presence of symptoms can be a good thing in that they can prompt people to consult a doctor for treatment and make them more compliant in taking their medications. Often, however, a person's first contact with a physician may be after significant damage to the end-organs has occurred. In many cases, a person visits or is brought to the doctor or an emergency room with a heart attack, stroke, kidney failure, or impaired vision (due to damage to the back part of the retina). Greater public awareness and frequent blood pressure screening may help to identify patients with undiagnosed high blood pressure before significant complications have developed. About one out of every 100 (1%) people with hypertension is diagnosed with severe high blood pressure (accelerated or malignant hypertension) at their first visit to the doctor. In these patients, the diastolic blood pressure (the minimum pressure) exceeds 140 mm Hg! Affected persons often experience severe headache, nausea, visual symptoms, dizziness, and sometimes kidney failure. Malignant hypertension is a medical emergency and requires urgent treatment to prevent a stroke (brain damage).

Diagnosis of Hypertension

Blood pressure is measured or tested by taking a blood pressure reading. It is measured using two numbers, (i.e.120/80mmHg). The "top" number is called the systolic number, which is a measurement of the pressure on the artery walls when the heart beats. The "bottom" number is the diastolic number, which is a measurement of the pressure on the artery walls when the heart is resting between beats. Many people think of a reading of 120/80mmHg as "normal". In fact there are many variations of normal that are dependent on a variety of factors. Unless a blood pressure reading is very high and needs to be addressed immediately, blood pressure readings need to be repeated, or monitored, over period of time to assess for trends and to get an idea of an overall blood pressure in an individual. Blood pressure readings also need to be evaluated for significance within the full context of a complete history and physical. As a very general guide, adults should keep their blood pressure below 140/90mmHg. In addition, current guidelines consider consistent readings over 120/80mmHg as "pre-hypertensive", which should be monitored and addressed to ensure blood pressure does not rise higher over time, and ideally stays below 120/80nnHg. Your healthcare provider will explain what your blood pressure readings mean for you and your health based on your individual case, current guidelines, and other factors.

Treatments of Hypertension

The most effective treatment plan for hypertension uses a multifaceted approach. Treatment plans are also individualized to best address the specific cause and the patient's age, medical history, and severity of hypertension. Hypertension is highly treatable and in most people, prompt and ongoing treatment will result in a normalization of blood pressure and in minimizing the risk of serious complications. Treatment begins with prevention. This includes maintaining a healthy weight, not drinking alcohol excessively, not smoking, eating a healthy-healthy diet, and getting regular exercise. These preventive measures are also generally recommended as treatment measures as well. Not all people can effectively manage their blood pressure by these lifestyle measures alone. For these people oral medications, known as anti-hypertensive drugs, may be prescribed. Individual medications may be used alone or in combination with other medications. Anti-hypertensive medications include diuretics, also known as "water pills", which lower blood pressure by stimulating the kidneys to flush extra fluid and salt from the body. ACE inhibitors lower blood pressure by preventing the body from making a hormone called angiotensin II, which narrows and tightens blood vessels. Angiotensin II receptor blockers protect blood vessels from the narrowing effects of angiotensin. Beta blockers help the heart to beat slower and less forcefully. Calcium channel blockers block calcium from entering the cells of the heart and blood vessels, resulting in relaxation of the vessels. Alpha blockers decrease nerve impulses that tighten blood vessels. Vasodilators relax and widen the blood vessels walls. Nervous system inhibitors work in the brain to increase messages to the blood vessels to relax and widen them. Treatment of hypertension also includes addressing underlying causes such as thyroid disease, obesity, and kidney disease. If hypertension is caused by a certain medication, then a dosage adjustment or different medication may be needed.

When to seek Medical Advice

  • You'll likely have your blood pressure taken as part of a routine doctor's appointment.
  • Ask your doctor for a blood pressure reading at least every two years starting at age 20. He or she will likely recommend more frequent readings if you've already been diagnosed with high blood pressure or other risk factors for cardiovascular disease. Children age 3 and older will usually have their blood pressure measured as a part of their yearly checkups.
  • If you don't regularly see your doctor, you may be able to get a free blood pressure screening at a health resource fair or other locations in your community. You can also find machines in some stores that will measure your blood pressure for free, but these machines can give you inaccurate results.

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