What is blood pressure variability and does it matter?

Blood pressure variability, the beat-to-beat, visit-to-visit, or day-to-day variation in blood pressure readings, is an independent cardiovascular risk factor: high blood pressure variability (particularly large visit-to-visit variability at clinic appointments over 1–2 years) predicts stroke, cardiovascular events, and mortality beyond average blood pressure level, suggesting that blood pressure instability itself is damaging regardless of mean level (Rothwell et al., Lancet, 201060574-8)).

The mechanism of visit-to-visit blood pressure variability causing cardiovascular harm: repeated large pressure swings stress arterial walls, accelerate arterial stiffness, and drive microembolic events in end organs (particularly the brain). Calcium channel blockers (specifically amlodipine) reduce blood pressure variability more effectively than other antihypertensive classes, which may partly explain their stroke risk reduction benefit beyond their average blood pressure lowering effect.

Honesty Scale: Solid (1) for blood pressure variability as an independent cardiovascular risk factor.

What to do: Keep a home blood pressure log recording readings at the same time each morning for 30 days. Calculate the range and standard deviation. If your readings vary by more than 20 mmHg systolic from day to day without an obvious explanation (illness, major stress), share the log with your physician, blood pressure variability data is clinically meaningful.

For the full picture, read The Blood Pressure Deep Dive