A single reading is a snapshot

Blood pressure moves with the day. Caffeine, traffic, a cold, a rushed appointment, all of it shows up in the number. What matters is what your readings look like across weeks, taken the same way each time.

Systolic, diastolic, and the gap between them

The top number measures the push as the heart contracts. The bottom measures the resting pressure between beats. Clinicians read both, plus the difference between them, because the pattern often says more than either value alone.

When to act

If two separate appointments land above 140 over 90, that is worth a plan rather than a repeat test. Bring home readings with you. Two a day for a week tells your clinician far more than one measurement taken in a hurry.