Hypertension is a major risk factor for cardiovascular disease . Numerous large-scale prospective
observational studies have demonstrated fi ve major eff ects of hypertension, all of which contribute to the
overall mortality and morbidity associated with hypertension. First, high blood pressure accelerates atherogenesis
and increases the risk for cardiovascular events twofold to threefold. Second, the level of systolic and
diastolic blood pressure is associated with cardiovascular events in a continuous, graded, and apparently
independent fashion. In subjects 50 years and older, an elevated systolic blood pressure is a much more
important cardiovascular risk factor than an elevated diastolic blood pressure .
Third, the risk for cardiovascular disease, beginning at 115/75 mm Hg, doubles with each increase of 20/10 mm Hg.
Between a diastolic blood pressure of 110 mm Hg and 70 mm Hg, a persistently lower usual diastolic blood
pressure of 5 mm Hg is associated with at least a 40% decrease in the incidence of stroke and a 21% decrease
in the incidence of coronary heart disease. Fourth, hypertension often occurs in association with, and as a
result of, other atherogenic risk factors, including dyslipidemia, glucose intolerance, hyperinsulinemia, and
obesity. Fifth, the association of hypertension with other cardiovascular risk factors increases the risk for cardiovascular events in a multiplicative rather than additive fashion.
Pharmacologic treatment of hypertension reduces the incidence of stroke and coronary artery disease, and
decreases mortality from cardiovascular causes in middle-aged and older adults . The results of the
randomized clinical trials of the treatment of hypertension indicate that the average percentage reductions in
the incidence of stroke, myocardial infarction, and heart failure with drug treatment are 35% to 40%, 20% to
25%, and 50%, respectively. If anything, these trials likely underestimate the cardiovascular benefi ts of blood
pressure control because numerous study patients assigned to active therapy stopped their treatment, whereas
others assigned to placebo were prescribed medications. In addition, the average duration of treatment was
only about 5 years, and most patients enrolled were at low risk for developing cardiovascular disease.
More recent clinical trials have focused on head-to-head comparisons of diff erent antihypertensive drugs
or combinations of drugs, to determine whether certain agents off er benefi ts beyond those attributable to
lowering of blood pressure, particularly in older persons with cardiovascular risk factors.
Meta-analyses ofthese trials have indicated that, with few exceptions, the most important factor in decreasing cardiovascular morbidity and mortality in hypertensive subjects is the magnitude of the blood pressure reduction rather than the drug or drugs used to achieve the reduction of the blood pressure. However, as indicated later, there are some compelling indications for the use of specifi c drug classes in appropriate patients. There is also evidence
that β-adrenergic blockers may not be as eff ective as other medications in preventing cardiovascular complications
in older people with hypertension.
Definition of Hypertension
Blood pressure is a continuous variable, and any level of blood pressure chosen to defi ne hypertension will be arbitrary. Nevertheless, an operational definition of hypertension has long been advocated by clinicians as a guideline for treatment. Such a definition should theoretically be based on the estimated level of blood pressure above which the benefit of pharmacologic therapy in reducing cardiovascular risk exceeds the risk and inconvenience of therapy. The report of the Seventh Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VII) recommended the classification of blood pressure for adults,
As compared with the previous classifi cation recommended by JNC VI, subjects with a blood pressure of 120/80 to
139/89 mm Hg are now designated as having prehypertension because they are at high risk for developing hypertension. Patients and clinicians need to be aware of this condition to ensure follow-up and institution of lifestyle modifications.
Hypertension is a major health problem throughout the world. The prevalence of hypertension worldwide may be
as high as 1 billion persons, and deaths attributed to hypertension now total about 7 million per year. The prevalence
of hypertension is higher in developed countries, but it is increasing rapidly in developing countries as a consequence of longer life span, obesity, and changing dietary habits. In the United States, even those who are normotensive at 55 years have a 90% lifetime risk for hypertension. According to the World Health Organization, suboptimal blood pressure is the number one attributable cause of death throughout the world. Hypertension is the most common cause of preventable death in developed countries.
About 95% of patients with elevated arterial pressure have essential hypertension. In many such patients, obesity is a
contributing factor. Obstructive sleep apnea is frequently associated with obesity and hypertension, but it has yet to
be definitively proved that appropriate treatment of this condition consistently lowers blood pressure. The remaining
5% of patients with high blood pressure have secondary hypertension . The prevalence of secondary
hypertension is higher in the very old and in the very young. Although patients with secondary hypertension are
few in number, it is important to identify such patients because their hypertension can often be cured or significantly improved by an interventional procedure, a specific drug therapy, or stopping a culprit drug.
Evidence of identifiable causes of hypertension should be sought in the initial history, physical examination, and
laboratory studies. Further diagnostic evaluation for causes of secondary hypertension should be pursued when the
presentation is atypical for essential hypertension, or when the initial evaluation suggests an identifiable cause.Diagnostic Approach.
The initial evaluation of the hypertensive patient should include the following steps:
• Confirmation of the presence of hypertension
• Determination of the presence and extent of target organ disease • Identification of cardiovascular risk factors and coexisting conditions that influence prognosis and therapy
• Exclusion or detection of identifiable causes of elevated blood pressure
These goals can usually be achieved with a comprehensive history, a thorough physical examination, and selected
A comprehensive history is essential, and should include the following:
• The duration and severity of elevated blood pressure, and the results of prior medication trials
• The presence of diabetes, hypercholesterolemia, tobacco use, and other cardiovascular risk factors
• A history or symptoms of target organ disease, including coronary heart disease and heart failure, cerebrovascular
disease, peripheral vascular disease, and renal disease
• Symptoms suggesting identifi able causes of hypertension
• The use of drugs or substances that may raise blood pressure
• Lifestyle factors, such as diet, leisure time physical activity, and weight gain, that may influence blood pressure
• Psychosocial and environmental factors, such as family support, income, and educational level, including factors
that could influence the efficacy of anti-hypertensive therapy
• Any family history of hypertension or cardiovascular disease
The physical examination should focus on determining the level of blood pressure and searching for evidence
of target organ disease or identifiable causes of hypertension.
Important facets of the examination include the following:
• Careful measurement of blood pressure
• Measurement of height and weight
• Funduscopic examination for hypertensive retinopathy
• Examination of the neck for carotid bruits, elevated
jugular venous pressure, and thyromegaly • Examination of the heart for abnormalities of the apical impulse or the presence of extra heart sounds or
• Examination of the abdomen for bruits, enlarged kidneys, and other masses
• Examination of the extremities for diminished arterial pulsations or peripheral edema
Laboratory studies are recommended to determine the presence of target organ damage and other cardiovascular
risk factors and to exclude identifiable causes of hypertension.
These include the following:
• Complete blood count
• Serum concentrations of potassium, creatinine, thyroidstimulating hormone, fasting glucose, and high-density
lipoprotein and total cholesterol
• Urinalysis for blood, protein, glucose, and microscopic examination
• An electrocardiogram
Management and Therapy
The principal goal in treatment of hypertension is to reduce the risk for cardiovascular morbidity and mortality.
The approach to therapy in an individual should be determined in part by the absolute risk for a cardiovascular
event, based on the presence of major cardiovascular risk factors or target organ damage. Patients with diabetes mellitus, chronic kidney disease, or clinical cardiovascular disease are at particularly high risk for cardiovascular
events. Pharmacologic therapy should be considered for these individuals when blood pressure is mildly elevated or
in the prehypertensive range, with a treatment goal of normalizing the pressure (i.e., <130/80 mm Hg). Lowerrisk
patients may benefit from a period of observation and lifestyle modification, using medical therapy if the average
systolic pressure exceeds 140 mm Hg or diastolic pressure exceeds 90 mm Hg over months of monitoring. The management strategy recommended in the JNC VII.
Lifestyle modifications are an important component of the therapy for high blood pressure. All patients with
hypertension, prehypertension, or a strong family history of hypertension should be encouraged to lose weight if
overweight, participate in regular aerobic exercise, limit alcohol intake, and adopt a healthy diet. The Dietary
Approaches to Stop Hypertension (DASH) eating plan, a diet rich in fruits, vegetables, and low-fat dairy products
with reduced saturated fats, is as effective as single-drug therapy in many hypertensive individuals. Additional
benefi t can be realized by limiting dietary sodium intake.
These lifestyle changes not only lower blood pressure but also enhance the effectiveness of antihypertensive drugs
and favorably infl uence other cardiovascular risk factors. Smoking cessation further reduces cardiovascular risk and
should be strongly encouraged.
Drug therapy is indicated if lifestyle modifications do not bring the blood pressure into the desired range. The optimal agent for initial therapy of uncomplicated patients with hypertension remains a subject of considerable
controversy. Thiazide diuretics, β-adrenergic receptor blockers, angiotensin-converting enzyme (ACE) inhibitors,
angiotensin-receptor blockers (ARBs), and calcium antagonists have all been viewed as appropriate first-line
agents for the treatment of hypertension. Thiazide diuretics are inexpensive and generally well-tolerated.