Essential hypertension usually causes no significant symptoms until complications in various organs occur. Symptoms vary widely, depending on the degree of blood pressure elevation and are divided into the following two categories:

• Mild, complicated hypertension: Dizziness, weakness, fatigue, headache, facial flushing
• Severe, complicated hypertension: Stroke, pulmonary edema, renal failure, encephalopathy accompanied by epileptic phenomena and altered mental status, heart failure, myocardial infarction [11] [12].

Essential hypertension is usually diagnosed during a routine check-up, or when a patient experiences mild, persistent symptomatology.

An accurate measurement of the patient's blood pressure is required in order to diagnose hypertension and, subsequently, essential hypertension. Blood pressure should be measured with a mercurial sphygmomanometer at least three times, with a two-minute interval between each measurement. The pressure should be assessed in both arms and one leg [13] [14].

During auscultation, the presence of a fourth cardiac sound indicates cardiac complications; pulses should also be palpated in the periphery. The region of the neck should be evaluated for the presence of distended jugular veins or carotid bruits.

With a reference to laboratory tests, a complete blood work, followed by a complete biochemical analysis is mandatory and includes the following:

• Hematocrit
• Complete blood count
• Liver function: AST, ALT, γ-GT, ALP
• HbA1c or fasting blood glucose
• Serum electrolytes (Na, K)
• Creatinine, Urea, GFR in order to evaluate renal function
• Complete serum lipid profile: total cholesterol, HDL, LDL, triglycerides
• Urinalysis

Depending on the symptoms a patient presents with, further procedures may be required, in order to eliminate other causes, such as chest X-ray.

In order to establish the diagnosis of essential hypertension, causes that are known to lead to an elevated blood pressure must be investigated. An magnetic resonance angiography (MRA), computed tomographic angiography (CTA) or an invasive renal angiography can help to determine whether the elevated blood pressure can be attributed to renal causes [15] [16]. An electrocardiogram, an echocardiogram and a stress echocardiogram can also provide useful information concerning cardiac involvement [17].

Despite the lack of established causes for essential hypertension, blood pressure can be maintained within the normal or nearly normal range with the daily administration of medications and lifestyle modifications.

Lifestyle modifications refer to the adherence to a more healthy lifestyle, without the factors that pose a threat to the cardiovascular system. Patients are asked to stop smoking, maintain a healthy weight, exercise, increase the consumption of fibers and vitamins and decrease the amount of Na they receive from their diet. Exercise should consist of aerobic training and the optimum BMI is between 18.5- 24.9 for patients diagnosed with hypertension. Food that is low in fat and especially saturated fat, should be preferred and the daily intake of salt should not exceed the limit of 2.4 g/day. The ingestion of alcohol should also be strictly regulated to no more than 29.5 ml per day (men) and 15 ml per day (women). Daily blood pressure measurements at home are advised and individuals affected by hypertension should also control other conditions that exacerbate the condition, such as diabetes and hyperlipidemia.

The initial treatment plan for patients with essential hypertension and no complications, diabetes, cardiovascular dysfunction or organ damage, solely includes lifestyle adaptations. Failure of these measures to render the patient normotensive indicates the need for anti-hypertensive medication. It should be noted that patients who do not fit the aforementioned profile in terms of comorbidities or present with a blood pressure that exceeds 160/100 mmHg are treated with a combination of lifestyle changes and medications from the beginning.

There are various medications used to control hypertension: β-blockers, ACE inhibitors, aldosterone antagonists, angiotensin receptor blockers, calcium channel blockers and diuretics. Dosages are initiated at a low level and the therapeutic scheme almost invariably starts with the choice of one drug. Failure of the therapy to regulate blood pressure within the next month suggests the need for a second medication or a dosage increase.

Invasive procedures are also an option in cases of essential hypertension that does not respond to conservative treatment. They are primarily used for the treatment of hypertension caused by renal disease or as experimental treatments.

The best prognosis among hypertensive patients is reserved for those with a moderate increase in their blood pressure or those individuals with no hypertension-induced complications, such as cerebral events, cardiovascular events or retinal sequelae. Cerebral events comprise both hemorrhagic and ischemic strokes and carotid artery disease seems to affect hypertensive patients with a greater frequency. Patients who develop papilledema, arterial stenosis and sclerosis of the retina are faced with a poor prognosis.

Essential hypertension has no known causes, yet its etiology is believed to be multifactorial. A certain, non-clarified genetic predisposition has been proposed, alongside flaws in hemodynamics and various physiologic pathways, including the renin-angiotensin activation system.

The risk factors that pose a threat to the cardiovascular system also affect the possibility of developing essential hypertension. Such risk factors are obesity, diabetes, hyperlipidemia and aging. They are thought to trigger hypertension in younger patients with a genetic predisposition. Patients who have exceeded the 60th decade of their lives are believed to be more negatively affected by the increased consumption of sodium, in terms of hypertension occurrence.

Essential hypertension is commonly diagnosed among the American population and affects nearly 1/3 of the latter, simultaneously leading to an elevated risk of cardiovascular and cerebral events [1] [2] [3]. The condition seems to affect non-Hispanic Afro-Americans at increased frequency, when compared with the Caucasian population and Mexican Americans [4] [5] [6].

The unknown and multi-factorial etiology of essential hypertension implies a complex and undefined pathophysiological mechanism [7]. Hypertension is a result of the interaction of many defects in the following physiologic components:

• Blood volume and viscosity
• Reactivity of the vascular system
• Cardiac output
• Neural stimulation
• Humoral mediators
• Vascular elasticity

Various studies have identified the contribution of inflammatory mediators in the pathogenesis of hypertension. The activation of cytokines such as interleukin 17, TNF-α and other molecules have been strongly associated with the occurrence of essential hypertension. The defective activation of the sympathetic nervous system is also believed to promote the clustering of inflammation mediators, thus further exacerbating hypertension: this activation is most likely affected by an abnormal transportation of Na across the cellular wall, by augmented Na permeability or by a dysfunctional Na-K pump [8] [9]. Psychological factors, such as emotional stress, are also known to lead to hypertension episodes, possibly through cortisol reactivity [10].

The renin-angiotensin-aldosterone complex is a system that is known to have the ability to cause the elevation of blood pressure. Renin is an enzyme that induces the conversion of angiotensinogen to angiotensin I; the latter is converted to angiotensin II, which causes vasoconstriction and the release of aldosterone and ADH by the sympathetic nervous system, thus leading to an increased blood pressure. This mechanism underlies secondary hypertension attributed to renal causes and could possibly play a role in primary hypertension as well, although its contribution has not yet been confirmed.

Lastly, hypertension is not solely caused by the abundance of a vasoconstricting agent, but can also be induced by the decreased concentration of a vasodilator. Various renal pathologies are associated with decreased production of vasodilators, but the potential mechanism in terms of essential hypertension has also not yet been definitively clarified.

Hypertension can be prevented to a significant degree, by means of adopting a more healthy lifestyle. The following recommendations can, in many cases, help an individual to avoid the onset of the condition:

• Avoiding food that is rich in saturated fat
• Consumption of alcohol that does not exceed one drink per day for women and two drinks per day for men
• Aerobic exercise, approximately for 30 min., most days of the week
• Cessation of smoking
• Reduction of daily sodium ingestion
• Consumption of fiber-rich foods, such as fruits and vegetables
• Reduction of emotional stress
• Healthy body weight

Hypertension is a condition which involves a persistently increased systolic blood pressure ≥ 140 mm Hg, diastolic blood pressure ≥ 90 mm Hg, or both, with the measurement performed at rest. Secondary hypertension can arise as a complication of another pre-existing condition, most commonly chronic kidney disease or primary aldosteronism, whereas essential hypertension occurs idiopathically, with no known etiology. Essential hypertension is otherwise referred to as primary hypertension.

Essential hypertension is a condition that affects the vast majority of the late-adult population of the western world, since the risk of being affected by it reaches 90%. It should be medically addressed and regulated, since elevated blood pressure can lead to various sequelae of cerebral, cardiac or renal nature. Even though its causes remain unknown, individuals at a high risk of developing hypertension are those who share the following risk factors:

• Advanced age
• Diabetes mellitus
• Obesity
• Insulin resistance
• Hyperlipidemia

Essential hypertension usually does not cause acute, life-threatening events; nevertheless, prolonged periods of elevated blood pressure can eventually lead to major complications, including a stroke, kidney failure or myocardial infarction.

Primary hypertension is treated with daily ingestion of antihypertensive drugs, which do not cure the condition but help to maintain blood pressure either within a normal range or within a range that does not constitute a cardiovascular, renal or cerebral threat. In spite of the extensive availability and variety of antihypertensive medication used to control the condition in patients with various comorbidities and characteristics, essential hypertension very often remains unregulated.

Hypertension is a condition in which the blood pressure is constantly elevated above normal limits while an individual is resting. It can arise as a complication of other conditions, primarily renal conditions (secondary hypertension) or occur spontaneously, without any known cause referred to as primary or essential hypertension.

Essential hypertension is indeed a frequent condition, estimated to affect nearly 30% of the population of the industrialized world. Even though the medical community has not yet discovered its exact causes and mechanisms, these are certain risk factors believed to increase a person's chances of developing essential hypertension. These risk factors include an increased body weight, progressed age, diabetes, smoking, high serum cholesterol, lack of exercise and an increased intake of sodium (salt) through one's diet. Hypertension is believed to have some genetic background and people who are genetically more prone to develop it might do so at a younger age, if their lifestyle features some of the previously mentioned risk factors.

Hypertension is a condition that cannot be cured, but the blood pressure can be kept within a normal range or within a range that does not pose a threat to other organs, such as the brain, heart, retina or kidneys. It does not cause symptoms, unless a complication has occurred, whether mild or severe. Moderate symptoms are dizziness, fatigue, headache and other, whereas more severe symptomatology includes a stroke, heart attack or encephalopathy. Severe complications usually arise if blood pressure has been too high for a long period of time, with no treatment.

Hypertension can be treated with lifestyle modifications that include less sodium in one's diet, the cessation of smoking, exercising regularly, keeping one's weight within healthy limits and reducing the amount of alcohol one consumes. If these changes are not enough to normalize the blood pressure, a patient is in need of medication. These drugs help to regulate blood pressure and must be ingested for the rest of the individual's life.

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