Blood pressure refers to the pressure in the arteries. The blood pumped out by the heart puts pressure or tension on the artery walls. Hypertension or high blood pressure refers to the pressure in the arteries which remains elevated over time.
This increased blood pressure has profound effects on the circulatory system which ultimately may lead to serious medical problems such as stroke, kidney failure and heart failure.
It is important to detect hypertension before it causes any damage. Hypertension is often called a silent killer because it often does not cause any symptoms until target organs have been severely damaged. Blood pressure is measured using an instrument known as a sphygmomanometer.
A standard sphygmomanometer is pressure gauge with an inflatable cuff attached. A stethoscope is used to listen to the sounds of blood pulsing through an artery. Blood pressure is recorded as two numbers in millimeters of mercury (mmHg), the first number is known as the Systolic blood pressure and the second number is known as the Diastolic blood pressure, for example 110/70 mmHg.
The systolic pressure is the maximum pressure in the artery as the heart contracts while the diastolic pressure is the lowest pressure in the artery in between heart contractions.
The preferred method for blood pressure measurement is auscultation. Aneroid manometers are also used to measure blood pressure and are accurate when calibrated on a semiannual basis. Ambulatory blood pressure monitoring (ABPM) requires a patient to wear a portable monitor that records blood pressure over a specified period.
For blood pressure to be effectively measured, the patient should be in the sitting position after resting for five to ten minutes. The patient must not have smoked, drank coffee, alcohol or tea within the last 30 minutes. Use an appropriately sized cuff, usually 12 cm for normal arm sizes or 15 cm for arms with larger sizes. Using an inappropriately sized cuff may result in an overestimation of blood pressure. The patient should sit comfortably in a chair with the right or left arm outstretched,
depending on which arm is to be used. The examiner, after application of the cuff, puts the bell of the stethoscope over the brachial artery at the elbow. The cuff is inflated to over 200 mmHg using a bulb attached by a tube to the cuff. The cuff is then deflated slowly until a series of tap-tap-tap or pounding sounds are heard over the stethoscope.
The pressure reading on the sphygmomanometer at the appearance of the sounds is the Systolic blood pressure. Diastolic blood pressure is measured at the disappearance of the sounds except in pregnancy where muffling of the sounds occur.
The systolic and the diastolic blood pressures should be recorded. The blood pressure should be the lowest diastolic blood pressure with its matching systolic blood pressure of two readings taken two minutes apart at one visit. The blood pressure should be repeated three times at intervals of 1-2 days before a person is labeled as hypertensive. Both numbers in a blood pressure test are important, but for people who are age 50 or older, systolic pressure gives the most accurate diagnosis of high blood pressure. Hypertension exists if the systolic pressure (first number) is 140 or higher, or if the diastolic pressure (second number) is 90 or higher. Normal blood pressure is less than 120 systolic and less
than 80 diastolic. Blood pressures between 120/80 and 140/90 are called Prehypertension.
by Okukpon Oziegbe Pierre
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