24 hour blood pressure monitoring In some cases, your doctor may recommend 24-hour or ambulatory blood pressure monitoring (ABPM). This is where your blood pressure is tested automatically around every 30 minutes over a 24-hour period using a cuff attached to a portable device worn on your waist. ABPM can help to give a clear picture of how your blood pressure changes over the course of a day. You should continue with your normal daily activities during the test, although you must avoid getting the equipment wet.