ambulatory blood pressure monitoring

A single clinic reading is a snapshot; ambulatory blood pressure monitoring is a time-lapse film. The person wears a small automated cuff connected to a recorder for a full 24 hours, going about ordinary life and sleep while the device takes readings automatically, typically every 15 to 30 minutes during the day and less often at night.

This produces a far richer picture than office readings alone. It can confirm or rule out white-coat hypertension, uncover masked hypertension that the clinic misses, and reveal the normal overnight dip in pressure. People whose pressure fails to fall at night (so-called non-dippers) carry higher cardiovascular risk, information that a few clinic visits could never provide.

Because out-of-office pressure predicts long-term outcomes better than clinic pressure, ambulatory monitoring is regarded by many guidelines as a reference standard for confirming a diagnosis of hypertension before committing someone to lifelong treatment. Its main limitations are availability, cost, and the mild inconvenience of the cuff inflating during sleep.