Blood Pressure

Definition

Blood pressure (BP) is the pressure exerted by circulating blood on the walls of arteries. It has two components: systolic (during ventricular contraction) and diastolic (during ventricular relaxation).

Classification (AHA/ACC)

• Normal: Less than 120/80 mmHg
• Elevated: 120 to 129/less than 80
• Stage 1 HTN: 130 to 139/80 to 89
• Stage 2 HTN: ≥ 140/≥ 90
• Hypertensive crisis: > 180/> 120. Emergency

Factors Affecting BP

Cardiac output, blood volume, peripheral vascular resistance, arterial elasticity, emotional state, activity, age, medications.

Measurement Technique

Use appropriate cuff size (bladder 80% arm circumference, width 40%). Support arm at heart level. Avoid BP measurement on side of mastectomy, dialysis fistula, or IV. Two readings 1 to 2 minutes apart; average the values.

Nursing Considerations

Orthostatic hypotension: BP drop greater than 20 systolic or 10 diastolic with position change (fall risk). Hypertensive urgency vs emergency (end-organ damage).

NCLEX Relevance

Must know normal ranges, hypertensive crisis thresholds, and proper technique.