How to Measure Blood Pressure: Monitor, Diary, and Measurement Accuracy

Blood pressure is the force with which blood presses against the walls of arteries during the heart's work. Measuring blood pressure takes a couple of minutes, but with improper preparation the result may be false. Let's discuss what a blood pressure monitor is, how to measure pressure correctly, and why a blood pressure diary is needed.

Blood Pressure Measurement: What It Is and Why It's Needed

Checking pressure shows whether it is too high or too low. High pressure usually has no symptoms, and the only way to detect it is to measure. Without control, it increases the risk of stroke, heart disease, vision problems, and chronic kidney disease. Low pressure may manifest as dizziness or fainting.

Pressure checks are suggested during a general examination, when taking medications for chronic conditions, in the hospital, during pregnancy. This is especially relevant for people aged 40 and older, those with close relatives with hypertension, smokers, those with excess alcohol or caffeine, excess salt, or obesity. Blood pressure can be measured at a pharmacy, with a family doctor, at some workplaces; for people aged 40 and older, some pharmacies do this for free.

Blood Pressure Monitor: What Kind of Device It Is and What Types Exist

A blood pressure monitor is a diagnostic device for measuring arterial pressure. Home models usually consist of an upper-arm cuff and a small device that displays the numbers. The cuff inflates, squeezes the arm for seconds, then air is released, and the device records the readings. Devices vary, so the instructions for your device must be followed literally.

How Pressure Is Measured: General Principles of the Procedure

Sit on a chair with back support, do not cross your legs, feet on the floor. Place your arm on the table so that the shoulder is at heart level. Roll up your sleeve: the fabric should not constrict the shoulder. The lower edge of the cuff should be about 2.5 cm above the elbow crease. Before measurement, empty your bladder, do not measure pressure after stress, food, caffeine, tobacco in the last 30 minutes, or recent exertion. Rest for at least 5 minutes, preferably 10.

• Take 2–3 measurements in one session with a 1-minute interval, remaining seated.
• Record the time of each measurement.
• At home, pressure is usually measured in the morning before breakfast and in the evening before dinner for 5 days — this gives at least 10 readings.
• Too slow inflation of the cuff or insufficient pressure in it gives a false result.

Can an Electronic Monitor Overestimate Pressure

A false result is possible with too slow inflation of the cuff or insufficient pressure in it; in addition, stress, food, caffeine, tobacco, and recent exertion affect the numbers. Home readings are often more accurate than "office" ones: many people have higher pressure in the doctor's office than at home — this is the so-called white-coat hypertension. The accuracy of your device can be checked by asking the doctor to compare home numbers with those measured in the office. Pressure changes during the day: higher at work, lower at home and during sleep, rises sharply upon awakening.

Blood Pressure Diary: What Is Recorded in It and Why the Doctor Needs It

The diary records the time of each measurement and the obtained values of systolic and diastolic pressure. From these records, the doctor sees the picture over days rather than a single random result and can make decisions about tactics. Reference points: pressure 140/90 and above when measured by a healthcare professional and 135/85 and above when measured at home is considered high. Normal is systolic below 120 and diastolic below 80. Readings of 120–129 with diastolic below 80 are regarded as elevated pressure, 130/80–139/89 — as stage 1 hypertension, 140/90 and above — as stage 2.

When a Doctor Is Needed Based on Measurement Results

A planned visit is needed if home numbers regularly stay at 135/85 and above. Low pressure can cause dizziness or fainting, so such symptoms are evaluated by the doctor together with measurement results. The doctor evaluates the diary, compares home and office readings, and if necessary prescribes 24-hour monitoring: the device is worn at home, but it is placed and removed at a medical facility. For adults aged 18–39 with pressure below 120/80 and no risk factors, checks are done once every 3–5 years; for people aged 40 and older and those at risk — once a year.

Elevated pressure by itself is not a reason to call an ambulance. Call 103 or 112 for signs of stroke or heart attack — these are life-threatening conditions.

Pressure is like a manometer on a pipe: the number is correct only when the device is working and the measurement conditions are the same. The material is for reference and does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer