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. 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. The top number, the systolic blood pressure, corresponds to the pressure in the arteries as the heart contracts and pumps blood forward into the arteries. The bottom number, the diastolic pressure, represents the pressure in the arteries as the heart relaxes after the contraction. An elevation of the systolic and/or diastolic blood pressure increases the risk of developing heart disease, kidney (renal) disease, hardening of the arteries (atherosclerosis or arteriosclerosis), eye damage, and stroke (brain damage). These complications of hypertension are often referred to as end-organ damage because damage to these organs is the end result of chronic high blood pressure. For that reason, the diagnosis of high blood pressure is important It was previously thought that rises in diastolic blood pressure were a more important risk factor than systolic elevations, but it is now known that in people 50 years or older systolic hypertension represents a greater risk.

The blood pressure usually is measured with a small, portable instrument called a blood pressure cuff (sphygmomanometer). The instrument measures the blood pressure in units called millimeters of mercury (mm Hg).

Blood pressure can be affected by several factors, so it is important to standardize the environment when blood pressure is measured. For at least one hour before blood pressure is taken, avoid eating, strenuous exercise, smoking, and caffeine intake. Other stresses may alter the blood pressure and need to be considered when blood pressure is measured.

For some people, blood pressure readings lower than 140/90 may be a more appropriate normal cut-off level. For example, in certain situations, such as in patients with long duration kidney diseases that lose protein into the urine (proteinuria), the blood pressure is ideally kept at 130/80, or even lower. The purpose of reducing the blood pressure to this level in these patients is to slow the progression of kidney damage. Patients with diabetes may also benefit from blood pressure that is maintained at a level lower than 130/80 In line with the thinking that the risk of end-organ damage from high blood pressure represents a continuum, statistical analysis reveals that beginning at a blood pressure of 115/75 the risk of cardiovascular disease doubles with each increase in blood pressure of 20/10. This type of analysis has led to an ongoing "rethinking" in regard to who should be treated for hypertension, and what the goals of treatment should be.

Isolated systolic hypertension, however, is defined as a systolic pressure that is above 140 mm Hg with a diastolic pressure that still is below 90. This disorder primarily affects older people and is characterized by an increased pulse pressure. The pulse pressure is the difference between the systolic and diastolic blood pressures. An elevation of the systolic pressure without an elevation of the diastolic pressure, as in isolated systolic hypertension, therefore, increases the pulse pressure. Stiffening of the arteries contributes to this increase of the pulse pressure.

Once considered to be harmless, a high pulse pressure is now considered an important precursor or indicator of health problems and potential end-organ damage. Isolated systolic hypertension is associated with a two to four times increased future risk of an enlarged heart, a heart attack, a stroke, and death from heart disease or a stroke. Clinical studies in patients with isolated systolic hypertension have indicated that a reduction in systolic blood pressure by at least 20 mm to a level below 160 mm Hg reduces these increased risks.

A single elevated blood pressure reading in the doctor's office can be misleading because the elevation may be only temporary. It may be caused by a patient's anxiety related to the stress of the examination and fear that something will be wrong with his or her health. The initial visit to the physician's office is often the cause of an artificially high blood pressure that may disappear with repeated testing after rest and with follow-up visits and blood pressure checks. One out of four people that are thought to have mild hypertension actually may have normal blood pressure when they are outside the physician's office

However, caution is warranted in assessing a single elevated blood pressure reading white. An elevated blood pressure brought on by the stress and anxiety of a visit to the doctor may not necessarily always be a harmless finding since other stresses in a patient's life may also cause elevations in the blood pressure that are not ordinarily being measured. Monitoring blood pressure at home by blood pressure cuff or continuous monitoring equipment can help estimate the frequency and consistency of higher blood pressure readings. Additionally, conducting appropriate tests to search for any complications of hypertension can help evaluate the significance of variable blood pressure readings.

Borderline high blood pressure:
Borderline hypertension is defined as mildly elevated blood pressure higher than 140/90 mm Hg at some times, and lowers than that at other times. As in the case of single elevated blood pressure reading, patients with borderline hypertension need to have their blood pressure taken on several occasions and their end-organ damage assessed in order to establish whether their hypertension is significant.

People with borderline hypertension may have a tendency as they get older to develop more sustained or higher elevations of blood pressure. They have a modestly increased risk of developing heart-related disease. Therefore, even if the hypertension does not appear to be significant initially, people with borderline hypertension should have continuing follow-up of their blood pressure and monitoring for the complications of hypertension.

If, during the follow-up of a patient with borderline hypertension, the blood pressure becomes persistently higher than 140/ 90 mm Hg, an anti-hypertensive medication is usually started. Even if the diastolic pressure remains at a borderline level (usually under 90 mm Hg, yet persistently above 85).

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 a specific abnormality in one of the organs or systems of the body. 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, obesity, hereditary susceptibility, and kidney failure.

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. 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. 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. 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.

Certain chronic conditions also may increase your risk of high blood pressure, including high cholesterol, diabetes, kidney disease and sleep apnea. Sometimes pregnancy contributes to high blood pressure. This hypertension is secondary hypertension. This form of hypertension occurs as a result of other systemic causes which directly or indirectly influence control blood pressure.

Types of secondary hypertension:

• Renal hypertension


• Adrenal gland tumors


• Coarctation of the aorta


• The metabolic syndrome and obesity


• Pregnancy

Uncontrolled high blood pressure can lead to:

• Damage to your arteries.


• Heart failure.


• A blocked or ruptured blood vessel in your brain.


• Weakened and narrowed blood vessels in your kidneys.


• Thickened, narrowed or torn blood vessels in the eyes.


• Metabolic syndrome.

To control and prevent high blood here's what we you can do:

• Eat healthy foods.


• Maintain a healthy weight.


• Increase physical activity.


• Limit alcohol.


• Don't smoke.


• Manage stress.


• Practice slow, deep breathing.

To keep blood pressure under control:

• Measure your blood pressure at home.


• Take your medications properly.


• Schedule regular doctor visits.


• Adopt healthy habits.


• Manage stress.