Blood Pressure Measurement

The Blood Pressure Measurement has two numbers, Systolic pressure and Diastolic pressure. The normal blood pressure is: 120 (Systolic ) / 80 (Diastolic ) mmHg.

Systolic pressure, the pressure when your heart pushes blood out around your body, where Diastolic pressure, the pressure when your heart rests between beats and blood is pushed around your heart.

The blood pressure is measured in millimeters of mercury (mmHg).

Guidelines for Assessing Blood Pressure

Posture

Blood pressure obtained in the sitting position is recommended. The subject should sit quietly for 5 min, with the back supported and the arm supported at the level of the heart, before blood pressure is recorded.

Circumstances

1. No caffeine during the hour preceding the reading.
2. No smoking during the 30 min preceding the reading.
3. A quiet, warm setting.

Equipment

1. Cuff size: The bladder should encircle and cover two thirds of the length of the arm; if it does not, place the bladder over the brachial artery. If bladder is too short, misleading high readings may result.
2. Manometer: Aneroid gauges should be calibrated every 6 months against a mercury manometer.

See Also: Balance Tests

Blood Pressure Measurement Technique

Number of readings:

1. On each occasion, take at least two readings, separated by as much time as is practical. If readings vary by more than 5 mm Hg, take additional readings until two consecutive readings are close.
2. If the initial values are elevated, obtain two other sets of readings at least 1 week apart.
3. Initially, take pressure in both arms; if the pressures differ, use the arm with the higher pressure.
4. If the arm pressure is elevated, take the pressure in one leg (particularly in patients younger than 30 years of age).

Performance:

• Inflate the bladder quickly to a pressure 20 mm Hg greater than the systolic pressure, as recognized by disappearance of the radial pulse.
• Deflate the bladder by 3 mm Hg every second.
• Record the Korotkoff phase V (disappearance), except in children, in whom use of phase IV (muffling) may be preferable if disappearance of the sounds is not perceived.
• If the Korotkoff sounds are weak, have the patient raise the arm and open and close the hand 5–10 times, and then reinflate the bladder quickly.

Home blood pressure monitoring (HBPM)

Home blood pressure monitoring is a self-monitoring tool that can be incorporated into the care for patients with hypertension and is recommended by major guidelines.

A growing body of evidence supports the benefits of patient home blood pressure monitoring compared with office-based monitoring: these include improved control of BP, diagnosis of white-coat hypertension and prediction of cardiovascular risk. Furthermore, Home blood pressure monitoring is cheaper and easier to perform than 24-hour ambulatory BP monitoring (ABPM).

National Institute for Clinical Excellence (NICE) guidelines for HBPM recommend that when using HBPM to confirm a diagnosis of hypertension it is necessary to ensure that:

• for each BP recording, two consecutive measurements are taken, at least 1 minute apart with the person seated;
• BP is recorded twice daily, ideally in the morning and evening; and
• BP recording continues for at least 4 days, ideally for 7 days.

References & More

1. George J, MacDonald T. Home Blood Pressure Monitoring. Eur Cardiol. 2015 Dec;10(2):95-101. doi: 10.15420/ecr.2015.10.2.95. PMID: 30310433; PMCID: PMC6159400. Pubmed
2. https://www.nice.org.uk/guidance/cg127 NICE. Hypertension: Clinical management of primary hypertension in adults. Available at: (accessed 29 June 2015).
3. Kaplan NM, Deveraux RB, Miller HS: Systemic hyperextension, Med Sci Sports Exerc 26:S269, 1994.
4. McGrew CA: Clinical implications of the AHA preparticipation cardiovascular screening guidelines, Athletic Ther Today 5(4):55, 2000.
5. Orthopedic Physical Assessment by David J. Magee, 7th Edition.