ABPM is best for diagnosing hypertension in primary care.

Ambulatory blood pressure monitoring (ABPM) is more accurate than clinic and home monitoring in diagnosing hypertension. A diagnostic strategy for hypertension using ABPM following an initial raised clinic reading would reduce misdiagnosis and NHS costs. If the first and second measurements taken during a consultation are both > or = 140/90 mmHg, 24-hour ABPM should be used to confirm the diagnosis of hypertension. Home monitoring can be used to confirm the diagnosis if the patient cannot tolerate ABPM. In cases of severe hypertension (clinic BP > or = 180/110 mmHg) and evidence of target organ damage, antihypertensive drug treatment should be started immediately without waiting for the results of ABPM or home monitoring. ABPM estimates true mean BP more accurately than clinic measurement because multiple readings are taken. It has been shown to have better correlation with a range of cardiovascular outcomes and end organ damage, Out-of-office methods can enable a diagnosis to be made more quickly. The benefits of these techniques, in particular ABPM, include the correct diagnosis of white coat hypertension and improved diagnostic accuracy. The weight of evidence suggests ABPM is the best prognostic indicator, followed by home then clinic monitoring. Stage 1 patients should only be offered antihypertensives if they have increased cardiovascular risk due to concurrent diabetes, chronic kidney disease, established CVD, target organ damage or a 10-year CVD risk >20%. Stage 2 patients should all be offered antihypertensives following ABPM or home monitoring, irrespective of their background cardiovascular risk.