An accurate blood pressure measurement is a crucial element of your health. Readings are almost always subjected to errors in measurement. To obtain an appropriate blood pressure reading, certain guidelines should be followed. The individual should be relaxed, as anxiety shoots up blood pressure. This is also called white coat syndrome when the blood pressure increases upon seeing a nurse or a doctor. Physiologically, blood pressure of an individual varies during the course of a day. These variations are called as diurnal variations. In addition to physiological variations, factors like smoking also have a significant effect on blood pressure reading. Any physical activity can also alter blood pressure. American Heart Association (AHA) proposed the following guidelines to measure blood pressure accurately.
Sit comfortably with back supported, legs uncrossed. In a sitting position the diastolic blood pressure will be higher, andin supine or sleeping position, systolic blood pressure will be a bit lower.
On the arm on which the cuff is placed, heart and blood pressure measuring apparatus should be at the same level. Any change in the difference in the levels of any of the three will alter the reading.
Cuff should be placed directly on the skin of the arm. Avoid placing the cuff on any clothing.
The arm cuff should be the appropriate size. Undersized or oversized cuffs will alter the reading.
The cuff should encircle more than 80% of the circumference of the arm. In case of overweight individuals, a larger cuff should be used. In morbidly obese individuals, thigh cuffs can be used for arms.
The observer should deflate the cuff for every 2-3 mmHg so that the observer can record the blood pressure accurately.
The measurement should be recordedto the nearest 2mm Hg.
The observer and the subject should not talk or indulge in any physical activity while measuring the blood pressure.
If the initial reading is high or low, a repeat reading should be taken to ensure that the reading is accurate.
Smoking increases blood pressure. It must be avoided for a few hours before checking blood pressure.
Any strenuous activity may alter a blood pressure reading. Exercise or brisk walking should be avoided right before checking blood pressure. If the subject takes the stairs, he or she should rest for few minutes before checking blood pressure.
Even with the above measures, blood pressure reading may be slightly different when you repeat it few minutes later. You can repeat blood pressure 2-3 times and take an average of all the readings. Blood pressure reading with a mercury meter is more accurate than electronic meters. Wrist meters are less accurate than the meters that measure blood pressure in the arms. If you have any suspicion about your meter at home, take it to your doctor’s office and compare the readings to their meter. You can truly avoid unnecessary anxiety.
Information from Pickering TG, Hall JE, Appel LJ, Falkner BE, Graves J, Hill MN, et al.; Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Recommendations for blood pressure measurement in humans and experimental animals. Part 1: blood pressure measurement in humans. Hypertension 2005;45:142–61.