What is the interpretation of a blood pressure (BP) measurement?

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Last updated: March 29, 2025View editorial policy

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From the Guidelines

A blood pressure measurement consists of two numbers, such as 120/80 mmHg, representing systolic and diastolic pressure, with normal blood pressure generally considered below 120/80 mmHg, elevated blood pressure ranging from 120-129 systolic with diastolic below 80, Stage 1 hypertension being 130-139 systolic or 80-89 diastolic, and Stage 2 hypertension being 140/90 mmHg or higher, as defined by the 2017 American College of Cardiology/American Heart Association hypertension guideline 1.

Blood Pressure Classification

The classification of blood pressure is based on the average of at least 2 careful readings obtained on at least 2 separate occasions, with the following categories:

  • Normal: <120 mm Hg and <80 mm Hg
  • Elevated: 120–129 mm Hg and <80 mm Hg
  • Hypertension:
    • Stage 1: 130–139 mm Hg or 80–89 mm Hg
    • Stage 2: ≥140 mm Hg or ≥90 mm Hg

Accurate Blood Pressure Measurement

For accurate readings, it is essential to:

  • Sit quietly for 5 minutes before measurement
  • Avoid caffeine or exercise for 30 minutes prior
  • Empty your bladder
  • Sit with back supported and feet flat on the floor
  • Position your arm at heart level
  • Use a validated device, preferably in a clinical setting 1

Out-of-Office Blood Pressure Measurements

Out-of-office blood pressure measurements, such as ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM), are recommended to confirm the diagnosis of hypertension and titrate medication, as they can detect white coat hypertension and masked hypertension 1.

Importance of Blood Pressure Monitoring

Blood pressure monitoring is crucial for the management of hypertension, as it can predict clinical outcomes and improve clinical care, with self-measured blood pressure monitoring showing a lower blood pressure at 12 months than usual care 1.

From the Research

Interpretation of Blood Pressure Measurement

The interpretation of a blood pressure (BP) measurement is crucial in determining the risk of cardiovascular disease (CVD) and guiding treatment decisions.

  • A systolic blood pressure (SBP) of at least 130 mm Hg or a diastolic blood pressure (DBP) of at least 80 mm Hg is considered hypertensive 2.
  • The target BP is less than 130/80 mm Hg for adults under 65 years and an SBP of less than 130 mm Hg for adults 65 years and older 2.
  • A reduction in SBP of 10 mm Hg can decrease the risk of CVD events by approximately 20% to 30% 2.

Blood Pressure Targets

The American family physician recommends a target blood pressure of less than 140/90 mm Hg 3.

  • However, only 44% of US adults with hypertension have their SBP/DBP controlled to less than 140/90 mm Hg 2.
  • The goal of treatment is to achieve a BP target, which may require lifestyle modification and/or pharmacologic therapy 2, 3, 4.

Antihypertensive Drug Classes

Different antihypertensive drug classes have varying effects on blood pressure reduction and variability.

  • Calcium channel blockers (CCBs) and diuretics have been shown to have a greater reduction in short-term blood pressure variability (BPV) compared to other classes 5.
  • The combination of CCBs with diuretics may be the most efficient treatment in lowering BPV 5.
  • Diuretics and CCBs are more effective in elderly patients at lowering systolic blood pressure (SBP) compared to beta-blockers and angiotensin-converting enzyme (ACE) inhibitors 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Antihypertensive drug classes have different effects on short-term blood pressure variability in essential hypertension.

Hypertension research : official journal of the Japanese Society of Hypertension, 2014

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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