Short answer: Use a validated upper-arm cuff and log morning readings before caffeine. This is the only real way to know if it's working for you.
Why "validated" is a specific, checkable device qualifier
Not every home blood pressure monitor is equally accurate — specifying a validated upper-arm cuff directly points you toward a genuinely reliable measurement tool.
Why "before caffeine" is a specific, practical timing detail
Caffeine can temporarily affect blood pressure readings — this direct instruction helps you get a more consistent, comparable baseline each morning.
💡 Worth knowing: this is listed as the third of six specific steps in "Getting The Most From BloodPril" — a genuinely practical, actionable habit.