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TL;DR

Blood Pressure: Force of blood against arterial walls, measured in mmHg as systolic/diastolic. Normal: <120/80.

By Valenke Exam Prep Team·Last updated 2026-06-02

Blood Pressure

CNA NNAAPMEDICAL ASSISTANTNREMT EMTNREMT PARAMEDIC

Definition

Force of blood against arterial walls, measured in mmHg as systolic/diastolic. Normal: <120/80.

Overview

Blood pressure measures force during cardiac contraction (systolic) and relaxation (diastolic). Normal is <120/80 mmHg.

Classification

Technique

Auscultatory method: inflate above expected systolic, deflate 2–3 mmHg/sec. First Korotkoff sound = systolic; disappearance = diastolic.

Cuff bladder should be 40% of arm circumference, encircle 80% of arm. Wrong size is the #1 error.

Clinical Significance

Hypertension is the silent killer. Orthostatic hypotension: ≥20 mmHg systolic drop within 3 minutes of standing.

Narrowing pulse pressure in trauma suggests cardiac tamponade, tension pneumothorax, or hemorrhage.

Why It Matters

Tested on CNA, MA, EMT, and Paramedic exams. Cuff sizing is the most frequent exam topic.

Related Terms

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Frequently Asked Questions

Most common BP error?
Incorrect cuff size. Too small = falsely high; too large = falsely low.
What is orthostatic hypotension?
Drop of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing.
Why is pulse pressure important in trauma?
Narrowing indicates reduced cardiac output—early sign of tamponade, tension pneumothorax, or hemorrhage.