Hypertension is a major risk factor for stroke, myocardial infarction, vascular disease, and chronic kidney disease. Prehypertension, significantly increases stroke risk. It is reported that, after adjustment for multiple cardiovascular risk factors, pre-hypertension which is blood pressure range 120 to 139/80 to 89 millimeter of Mercury is associated with increased risk for stroke, compared with an optimal blood pressure. Patients in the high range of pre-hypertension, that is to say, 130 to 139/85 to 89 millimeter of Mercury have 95% increased risk of stroke, compared with 44% increased risk for those in the low range of prehypertension, which is 120 to 129/80 to 84 millimeter of Mercury.
Hypertension is defined as a systolic blood pressure of 140 millimeter of Mercury or more, or a diastolic blood pressure of 90 millimeter of Mercury or more, or taking antihypertensive medication. Based on recommendations of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, the classification of blood pressure for adults aged 18 years or older has been as follows: Normal blood pressure with systolic lower than 120 millimeter of Mercury and diastolic lower than 80 millimeter of Mercury. The Pre-Hypertensive patients are those who are with systolic of 120 to 139 millimeter of Mercury and diastolic of 80 to 89 millimeter of Mercury. Stage 1 hypertensive patients have the systolics ranging 140 to 159 millimeter of Mercury and diastolic anywhere between 90 to 99 millimeter of Mercury. Stage 2 hypertension is diagnosed when systolics are consistently in the 160 or greater range and diastolic of 100 millimeter of Mercury or greater.
Hypertension may be primary, which may develop as a result of environmental or genetic causes, or secondary, which has multiple etiologies, including renal, vascular, and endocrine causes. Primary or essential hypertension accounts for 90-95% of adult cases, and secondary hypertension accounts for 2-10% of cases.
The evaluation of hypertension involves, accurately measuring the patient’s blood pressure, taking a focused medical history, performing a thorough physical examination, and obtaining results of routine laboratory studies. A 12-lead electrocardiogram should also be obtained. These measures help determine the presence of end-organ disease, possible causes of hypertension, cardiovascular risk factors, and as well gives baseline values for judging biochemical effects of therapy. Other studies may be obtained on the basis of clinical findings or in individuals with suspected secondary hypertension and/or evidence of target-organ disease, such as complete blood count, chest radiograph, uric acid, and urine microalbumin.
Guidelines from JNC, the American Diabetes Association and the American Heart Association/American Stroke Association recommend lifestyle modification as the first step in managing hypertension.
JNC’s recommendations to lower blood pressure and decrease cardiovascular disease risks include 2 or more lifestyle modifications are combined. Weight Loss leads to dropping of systolic blood pressure by 5-20 millimeter of Mercury per 10 kg. Limiting alcohol intake to no more than 30 mL of ethanol per day for men and 15 mL of ethanol per day for women helps the blood pressure to drop by 2-4 millimeter of Mercury. Reducing Sodium Intake to no more than 2.4 grams of sodium or 6 grams of sodium chloride leads to reduction of 2-8 millimeter of Mercury. Maintaining adequate Intake of Dietary Potassium, approximately 90 millimoles per day and adequate Dietary Calcium & Magnesium are some of the other lifestyle modifications advocated by JNC. Smoking cessation and reducing intake of Dietary Saturated Fat & Cholesterol is good for overall cardiovascular health. Engaging in Aerobic Exercise for at least 30 minutes daily for most days reduces the systolic blood pressure by 4-9 millimeter of Mercury.
The American Heart Association/American Stroke Association recommends a diet that is low in sodium, high in potassium along with consumption of fruits, vegetables, and low-fat dairy products to reduce blood pressure and lower the risk of stroke.
The 2013 European Society of Hypertension and the European Society of Cardiology guidelines recommend a low-sodium diet consisting of 5 to 6 grams per day as well as reducing body-mass index to 25 kg per meter square and waist circumference to less than 102 cm in men and 88 cm in women.
If lifestyle modifications are insufficient to achieve the goal blood pressure, there are several drug options for treating and managing hypertension. Thiazide diuretics are the preferred agents in the absence of compelling indications. Compelling indications may include high-risk conditions such as heart failure, ischemic heart disease, chronic kidney disease, and recurrent stroke, or those conditions commonly associated with hypertension, including diabetes and high coronary disease risk. Drug intolerability or contraindications may also be factors. Use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, and beta-blockers are all acceptable alternative agents in such compelling cases.