New guidance from NICE advocates 24-hour ambulatory blood pressure monitoring (ABPM) in patients suspected of having hypertension in part to rule out the "white coat effect".
The current practice of diagnosing chronic high blood pressure by averaging multiple readings often taken in a GP surgery using an inflatable arm cuff has numerous drawbacks.
NICE is now recommending that a diagnosis of hypertension should be made using 24-hour ambulatory blood pressure monitoring (ABPM). This should be offered to patients with a clinic blood pressure of 140/90 mmHg or higher. ABPM involves wearing a mobile blood pressure monitor that straps around the waist and records numerous blood pressure measurements throughout the day and night. The approach helps to avoid the white coat effect - where a patient experiences a temporary increase in blood pressure while having their blood pressure measured by a doctor.
Bryan Williams, Professor of Medicine at the University of Leicester and Chair of the Guideline Development Group, said: "The important recommendations in this guideline will affect the treatment of millions of people in our country and change the way blood pressure is diagnosed for the first time in more than a century.
"Blood pressure is highly variable so we never use a single reading. Patients are asked to come in and see their GP on at least 2 further occasions. But with AMBP, BP is monitoring throughout the day and then an average value is taken.
"This is done away from the doctor's office, so it is a more natural environment and the results are available after a single day."
Professor Mark Caulfield, President of the British Hypertension Society and a member of the Guideline Development Group, added: "The cost of treating people with hypertension is now cheaper than doing nothing. If left untreated, hypertension will go on to be a greater cost to the NHS through strokes and heart attacks."
Professor Richard McManus, Professor of Primary Care Cardiovascular Research at the University of Birmingham, who is also a GP and was involved in the development of the guidelines, agreed that cost savings could be made but warned that currently not all practices had the right equipment in place.
"The biggest challenge for GPs will be around purchasing the ABPM equipment. Smaller practices may well need to share equipment. But with practices banding together into consortia, this may be the ideal way for practices to share equipment," he said.