Ambulatory blood pressure monitoring (ABPM) is a method of taking regular blood pressure readings, usually over a 24-hour period, as patients conduct their normal activities. A special, automatic blood pressure monitor is used, and patients are asked to keep a diary or log of their activities during the day.

Ambulatory blood pressure monitoring is usually used when a physician suspects that a patient is suffering from "white coat hypertension." This is a condition in which high blood pressure occurs only in the physician’s office as a result of stress and anxiety.

However, there are a number of other situations that might cause a physician to recommend ambulatory blood pressure monitoring. These include patients who do not respond to medication and patients with symptoms such as fainting (syncope). In addition, ABPM has been found to be a more accurate predictor of patients at high risk of a cardiac event than than other blood pressure monitoring methods.

Ambulatory blood pressure monitoring is distinguished from home blood pressure testing. Home monitoring systems are gaining in popularity. Relatively inexpensive, they allow people to take their own blood pressure at various times throughout the day. Though this can yield valuable information, there are several drawbacks when compared to ambulatory blood pressure monitoring.

ABPM uses specialized equipment to measure blood pressure at regular intervals, 24 hours a day. This information is combined with a written log to aid in the diagnosis and/or treatment of conditions related to blood pressure.