High Blood Pressure

High blood pressure or hypertension is an increase in the lateral pressure exerted on the walls of the arteries above normal level (ideally 120/80 mm Hg). There is no rigidly defined threshold level of blood pressure which defines risk from safety and the standards vary with age, sex, geographical distribution, height, weight, diet especially sodium intake, hormonal factors, and so forth. Regardless, the current international standards is set on a diastolic pressure greater than or equal to 90 mm Hg or a systolic pressure of greater than or equal to 140 mm Hg is considered to constitute high blood pressure or more aptly hypertension. Systolic blood pressure is the recording taken when the heart is in a state of contraction, while diastolic blood pressure is taken when the heart is relaxed.

Screening programs reveal that 800 million individuals worldwide are affected by hypertension, constituting about 25 percent of general population. The prevalence and vulnerability to complications increases with age. For obscure reasons, the incidence is high in African Americans. It accounts for 20 to 50 percent of all deaths. Epidemiological data reveal that systolic blood pressure is more important than diastolic blood pressure as a risk factor for cardiovascular diseases, except for young patients.

Hypertension is one of the chronic diseases that has shown the largest decline in mortality over the past four decades. Although the number of deaths in women exceeds those in men, the rate of fall is similar in both sexes. This fall is attributable to the introduction of effective drugs during the past 15 to 20 years.

The cardiovascular system is a very dynamic system facing normal variations in blood pressure during course of the day, variations in emotions, excitement, stress, environment, and so forth because normal blood pressure is the outcome of interplay of many factors. For example, blood pressure is at its peak early morning just before waking up due to a surge of adrenocorticoid hormone. However, such a variation during time of the day (diurnal variation) is considered essentially normal and not as part of any disease process. Similarly, an anxious examinee might show an exaggerated elevation in blood pres-sure—so-called “white coat” hypertension. Repeated measurements, made on separate occasions, in a stress-free environment are required for a definitive diagnosis of hypertension.

High blood pressure is not only one of the major risk factors for most forms of cardiovascular disease, but it is also a condition with its own risk factors. The World Health Organization (WHO) has reviewed the risk factors for essential hypertension as nonmodifiable and modifiable risk factors. Age, gender, genetic factors, and ethnicity are those risk factors that are beyond human manipulation. However, those contributing entities that can be artfully tailored according to personal requirements are weight, salt intake, and low consumption of saturated fat, alcohol, and oral contraceptives, which are an important cause of increased arterial pressure in females. Use of unrefined foods including more fiber and bran, active lifestyle, avoidance of stress, and improvement of socioeconomic status in monetarily deprived countries are important preventive strategies unanimously devised by researchers and practitioners.

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