Diagnosis of High Blood Pressure

Blood pressure measurement in the clinic plays a key role in detecting and monitoring high blood pressure. Accurate assessment requires standardised measurement conditions, including a quiet and comfortable environment. 

In the hypertension clinic, validated automated blood pressure monitors are used. These devices are regularly calibrated, and cuffs of different sizes are available to ensure an appropriate fit for each individual. 

Before measuring blood pressure, it is recommended that the person: 

• Avoids coffee, alcohol, smoking and physical activity for at least 30 minutes beforehand. 

• Rests for at least 5 minutes before the measurement. 

• Sits with their back supported, feet flat on the floor and legs uncrossed. 

• Keeps their arm supported at heart level. 

• Avoids talking during the measurement. 

The cuff should be placed around the upper arm, directly on the skin or over a thin layer of clothing. It should be secure, but not overly tight. Thick sleeves should be removed and not rolled up, as they may affect the result.

First visit 

During the first visit, it is recommended to measure blood pressure in both arms to identify any possible differences between them. During subsequent visits, the arm that showed the higher blood pressure readings should be used as the reference. 

At each visit, three blood pressure measurements are usually taken, with 1–2 minutes between each reading. If there is a significant difference between the first two measurements, additional readings may be performed. The recorded blood pressure value corresponds to the average of the last two measurements. 

In some people, especially older adults, those with diabetes, or those who experience dizziness, blood pressure may also be checked while standing to assess for orthostatic hypotension. Measurements are usually taken after 1 and 3 minutes of standing. 

Follow-up visits 

During follow-up visits, blood pressure is measured in the reference arm, under the same resting conditions and using the same measurement technique. As a routine practice, three measurements are taken, with 1-2 minutes between each reading, and the average of the last two measurements is recorded. 

Ambulatory blood pressure measurement (ABPM) is a non-invasive test that allows blood pressure to be automatically measured over a 24-hour period while the person carries out their usual daily activities and during sleep. 

To perform the test, a cuff is placed around the arm and connected to a portable device that performs measurements at regular intervals, typically every 20 minutes during the day and every 30 minutes at night. 

ABPM provides particularly useful information by assessing blood pressure patterns outside the clinical setting, including nighttime blood pressure levels, and helps identify situations such as white-coat hypertension or masked hypertension. 

Home blood pressure measurement (HBPM) consists of measuring blood pressure outside the clinical setting, usually at home, either by the patient themselves or with the assistance of family members or caregivers. 

Together with ambulatory blood pressure measurement (ABPM), HBPM provides valuable additional information to confirm a diagnosis of hypertension, monitor blood pressure control, and guide treatment adjustments when necessary. 

Despite being a simple method, it should be performed carefully and according to a standardised protocol. Validated automatic devices should be used, preferably upper-arm monitors, and measurements should be performed according to healthcare professionals’ recommendations regarding the number of measurements, the timing of readings, and the recording of results. 

To verify whether a blood pressure monitor has been validated, you can consult the international list of validated devices on STRIDE BP.