Menu
How to measure office blood pressure and what does it reveal? A guide for clinicians
There are many cardiovascular health parameters and nearly as many diagnostic devices for their measurement, but few as universal as blood pressure (BP). However, it is essential how to measure blood pressure and interpret it correctly. Let us have a look. At the end of the article, you can also find a handy brochure with all the essential BP information for your office.
In this blog you will learn:
Why is blood pressure important?
The importance of BP and its measurement is built into every physician before they even leave medical school. Blood pressure is important for three reasons. Firstly, it reflects physical and mental events in the body. Secondly, it always has an effect on the body. Thirdly, it can be instrumental in detecting various conditions and cardiovascular risk calculation. If we discover abnormal blood pressure and start treatment on time, serious events like heart attack, heart failure, ischemic heart disease and even death might be avoided.
A detailed presentation of the various aspects of blood pressure, its measurement and interpretation is provided in this video lecture by Dr Jana Brguljan Hitij [1]:
How to measure blood pressure at the office?
Low, normal and high blood pressure
It is essential to note that ‘low’, ‘high’ and ‘normal’ blood pressure are tentative points along the blood pressure continuum, with many gray areas in-between.
For example, high normal blood pressure can affect a person considerably over a period of time. The Framingham heart study shows that cardiovascular events are much more frequent with people with high normal blood pressure than those with normal blood pressure [1].
Both high and low blood pressure can be damaging to the human body, necessitating regular BP check-ups in at-risk patients. Let us have a look at what they are and what comorbid conditions can be dangerous for the patient.
Hypertension
Hypertension, consistently raised blood pressure, is an important risk factor for a variety of CVDs and cardiovascular system-related conditions, specifically for those of atherosclerotic aetiology (hypertension itself is a risk factor for atherosclerosis) [3, 4, 5]. This includes coronary artery disease (CAD), which is 2.3 times deadlier in hypertensive patients, stroke, cognitive decline, dementia and retinopathy [6, 7, 8]. Lastly, hypertension is a risk factor for peripheral artery disease (PAD) and chronic kidney disease (CKD) [9, 10].
There are several well-defined risk factors for hypertension, classified as an office BP ≥ 140/90 mmHg, although their exact contribution to hypertension and its severity is difficult to determine [11]. The vast majority, up to 95% of hypertensive patients have essential (idiopathic) hypertension, i.e. with no identifiable cause [12]. Secondary hypertension affects the remaining 5% of patients with hypertension and has an identifiable cause— one of the most common is renal artery stenosis.
Office blood pressure measurement, however, may not be enough to discover the following, very frequent types of hypertension.
White coat hypertension
White coat hypertension (WHT) is the raised blood pressure that appears when the patient feels stressed in a healthcare setting; the patient’s blood pressure is normal under other circumstances, e.g. at home. However, studies suggest that the patient’s true blood pressure reflects better with 30-minute office blood pressure measurement. This is a sequence of measurements rather than just a few like in the standard office blood pressure measurement procedure [13].
Masked hypertension
Masked hypertension is very difficult to detect at the doctor’s office because the patient’s blood pressure may only rise abnormally on an irregular basis, e.g. during certain activities that are not present in the healthcare setting.
If suspecting that white coat or masked hypertension might be present, ambulatory blood pressure measurement (where a device is attached to the patient for up to 24 hours) or regular home blood pressure measurements should be performed. The important of home BP measurement can not be stressed enough because the amount of BP control is very low worldwide. This is unnecessary as commercially available home use blood pressure devices are easily obtained:
We always advise people that, just like they have a thermometer, they should have BP machines. Those must be validated and reliable, and the upper arm cuff should be used.
(Dr Jana Brguljan Hitij)
Hypotension
Compared to hypertension, hypotension is more of a physiological state than a condition (disease). Regarded as a BP of 90/60 mmHg or less, it is generally not an issue in otherwise healthy patients without symptoms, and is often associated with good health and fitness. It is also less well-known among the general public because there are generally no preventive programmes available.
Hypotension is most often caused by acute cardiovascular events, anaphylaxis, septic shock, some medications, endocrine issues and only rarely by lifestyle factors (e.g. vitamin B-12 and folic acid deficiency) [14]. Like in hypertension, there may be several, often overlapping and complex causative conditions. The most serious ones are acute conditions like haemorrhagic shock, heat exhaustion and heat stroke [15, 16].
Especially in old people, the condition known as orthostatic hypotension (postural hypotension) can appear. This means that the patient’s blood pressure drops when they stand up after sitting or lying down. This can result in a fall and injury [1].
Devices for effective office blood pressure measurement
Correct blood pressure treatment always starts with correct blood pressure numbers (measurements). In addition to the proper office blood pressure measuring technique above, it is essential to use a validated BP measuring device. In that case, office BP is simple to measure and can provide the clinician with a wealth of information.
There are many devices on the market, and they differ in their accuracy and ability. Some of them also excel in additional features that take this simple diagnostic procedure beyond BP measurement. For example, automatic entry of the measurements into the patient’s electric health record (EHR) and instant sharing of data with the patient’s doctor (e.g. if the measurement is not performed at the office) or with specialists can contribute to faster and more effective treatment.
Change how you measure blood pressure.
Assist. Prof. Jana Brguljan Hitij, MD, PhD
Specialist of internal medicine and cardiology
Dr Brguljan is head of the Hypertension Department at the University Medical Centre in Ljubljana. After finishing her medical studies in 1990, she continued her education as a researcher at the Catholic University of Leuven (Belgium), where she completed her master’s and PhD degrees. Her research focus is high normal blood pressure and the value of ambulatory blood pressure monitoring in the detection of masked hypertension. She is current president of Slovenian Hypertension Society, an active member of ESH and ESC, and an executive member of the Journal of Hypertension’s editorial board.