Hypertension, Part One: A Patient Guide
It is estimated that one in four adults (approximately 50 million) in the United States has elevated blood pressure - and more than 30 percent of them are unaware of it. Since people with hypertension may not exhibit any symptoms, their high blood pressure is often undiagnosed until complications occur. It has been proven that blood pressure screening facilitates early diagnosis and treatment. Proper treatment clearly reduces the risk of the complications associated with hypertension.
Blood pressure is the force exerted against artery walls as blood is carried through the circulatory system. The measurement of force is made in relation to the heart's pumping activity, and is measured in millimeters of mercury (mmHg). The higher number, or systolic pressure, is the measurement of pressure that occurs when the ventricle of the heart contracts or beats. The lower number, or diastolic pressure, is the measurement recorded between beats, while the heart is relaxed. The systolic number is placed over the diastolic number and is always the higher of the two numbers. For example, 110/70 (read as 110 over 70).
Elevated blood pressure or hypertension
The diagnosis of hypertension is made when the force required for blood flow is greater than normal. According to the Seventh Report of the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure (JNC VII), a blood pressure measurement of less than 120/80 mmHg is considered normal; 120-139/80-89 mmHg should be considered prehypertension; 140-159/90-99 mmHg is stage 1 hypertension; and greater than 160/at or greater than 100 mmHg is stage 2 hypertension. A diagnosis of hypertension is made when a person has had two or more elevated readings after the initial assessment. Readings are taken in a quiet room after relaxation. It is normal for the blood pressure to increase with exertion, or even with pain to a certain extent.
In people over the age of 50, systolic blood pressure (BP) of more than 140 mmHg is a much more important cardiovascular disease (CVD) risk factor than diastolic BP. In fact, the risk of CVD, beginning at 115/75 mmHg, doubles with each increment of 20/10 mmHg. Interestingly, the risk of hypertension increases with age and it has been estimated that despite normal blood pressure at the age of 55 there will still be a 90 percent lifetime risk for developing hypertension.
Plotting your blood pressure
The guidelines (JNC 7) in place now will be updated again before the end of the decade. For adult patients (aged 18 years old and over) who have not previously been treated for or been diagnosed as having hypertension, you are considered in one of the following categories:
Depending on your blood pressure certain treatments and management strategies will be chosen. Your category is chosen by the highest category reached. Thus if your blood pressure is 138/98 you have stage 1 hypertension. The goal of each is to get your blood pressure into the best range for you so that you may have the benefit of reduction of your risks toward normal. Treatment does not make you a non-hypertensive though. You will be at higher risk of problems related to hypertension than people without high blood pressure for the rest of your life. This means that you will have to continue to be concerned with your blood pressure for the rest of your life. The goal of the therapy is also to treat this silent problem without causing other problems like unbearable side effects from the medicines.
For almost all people defined as prehypertensive or hypertensive, lifestyle modifications should be recommended. These include reduction of excess salt intake, reduction of weight to the ideal body weight for your height, age and body structure, and an exercise program.
Hundreds of different types of medications can be prescribed for high blood pressure. Most patients will several in their lifetime. It is common to initially start with one medication at a time for patients who are prehypertensive. This entails thiazide-type diuretics for most. ACEI (angiotensin converting enzyme inhibitors), ARB (angiotensin type 1 receptor blockers) , BB (beta blocking agents), CCB (calcium channel blocking agents, or combinations are often considered depending upon the patient and presence or absence of other indications. We go more slowly with those at risk for sudden drops in blood pressure, and are more aggressive in those with chronic kidney disease. For most patients with stage 2 hypertension we anticipate that we will require at least a combination of antihypertensive medications.
Primary and secondary hypertension
Primary or essential hypertension has no known cause, however genetic and lifestyle factors such as body weight and salt consumption can contribute to high blood pressure. Eighty to ninety percent of persons diagnosed with hypertension fit in this category. The diagnosis is made when no other cause for the high blood pressure is found.
Secondary hypertension is caused by another medical condition such as a blockage of an artery to the kidney, adrenal and neurendocrine tumors, kidney disease, or pregnancy. Several medications including oral contraceptives prednisone, cyclosporine, and the intake of certain foodstuffs (licorice) may also cause hypertension as a drug-related side effect.
There are several factors that put people at risk for hypertension. Increasing age, gender, heredity and race are factors that cannot be controlled. Elderly individuals are especially encouraged to undergo regular screening for the presence of hypertension because the condition is so prevalent in this population and is treatable once identified. African Americans are at greater risk for developing hypertension than Caucasians.Controllable risk factors are lifestyle related: obesity, diet, lack of exercise, certain medications, smoking and excessive alcohol consumption.
Hypertension is called the silent killer because most of the time there are no symptoms and it therefore goes undiagnosed. The patient who has less access to medical care is therefore less likely to be diagnosed. When patients state that they "can tell" if their blood pressure is elevated they are wrong as often as they are right. If you are feeling any of the following however, you should seek medical attention and have your blood pressure checked: Headache, dizziness, irregular or rapid heartbeat, chest pains, shortness of breath, nosebleeds, fatigue and blurred vision.
National Heart, Lung, and Blood Institute. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Journal of the American Medical Association . May 2003; 289:2573-2574.
Virtual Hospital: Clinician's Handbook of Preventive Services. High Blood Pressure.
Office of Disease Prevention and Health Promotion - Public Health Service. How To Keep Your Blood Pressure Under Control.