How to measure blood pressure accurately at home

Why measure at home

• it detects white-coat hypertension (high only at the doctor) and masked hypertension (normal at the doctor, high in daily life)
• it shows whether medicines are working on ordinary days
• it makes you a participant in treatment, and often improves adherence

Home measurement does not replace the visit. Diagnosis and medicine changes are made by the doctor. When there is doubt, 24-hour blood pressure monitoring (ABPM) may also be needed.

Reading the values: mmHg and cmHg

In Albania blood pressure is usually spoken in cmHg (centimeters of mercury), while devices and international guidelines use mmHg (millimeters of mercury). It is the same measurement: 1 cmHg = 10 mmHg, so you simply divide by 10.

• 135/80 mmHg is said as "13.5 over 8".
• 120/80 mmHg is said as "12 over 8".
• 140/90 mmHg is said as "14 over 9" — the clinic threshold for high blood pressure.
• 180/120 mmHg is said as "18 over 12" — a very high value (see the emergency signs above).

The first number is the systolic (upper) pressure, the second the diastolic (lower). Most devices display mmHg; when you report a reading to your doctor, say which unit you mean to avoid confusion.

How blood pressure is written and said

Devices and international guidelines write blood pressure in mmHg (millimeters of mercury), while in Albania it is usually spoken in cmHg (centimeters of mercury). It is the same measurement: you simply divide by 10. On this page, values are written in the form 130/80 mmHg (said "13 over 8").

• 120/80 mmHg (said "12 over 8")
• 130/80 mmHg (said "13 over 8")
• 135/85 mmHg (said "13.5 over 8.5")
• 140/90 mmHg (said "14 over 9") — the clinic threshold for high blood pressure
• 180/120 mmHg (said "18 over 12") — a very high value (see the emergency signs above)

The first number is the systolic (upper) pressure, the second the diastolic (lower). When you report a reading to your doctor, say which unit you mean to avoid confusion.

Choosing the device

• Choose an automatic upper-arm cuff device that has been clinically validated (look for a list of validated devices or ask the pharmacist).
• Wrist or finger devices are not recommended as a first choice; they are less reliable.
• Devices with a large display and memory make record-keeping easier.
• Check your device against the doctor’s once: measure with both during a visit.

The right cuff

The wrong cuff size is one of the most common mistakes: a cuff that is too small raises the measured pressure, and one that is too large lowers it.

• arm circumference 22–26 cm — small adult cuff
• 27–34 cm — standard adult cuff
• 35–44 cm — large cuff
• 45–52 cm — extra-large cuff

Measure the arm at the midpoint between the shoulder and the elbow. The cuff goes directly on bare skin, not over thick sleeves.

The measuring routine

1. For 30 minutes before: no smoking, no coffee, no exercise. Empty your bladder.
2. Sit for 5 minutes in quiet, back supported, feet flat on the floor and uncrossed.
3. Rest your arm on a table, with the cuff at heart level.
4. Do not talk or move during the measurement.
5. Take two readings one minute apart, in the morning (before medicines) and in the evening.
6. Do this for 7 days in a row before the visit; discard the first day, and calculate the average of the rest.

At first measure both arms; afterwards use the arm with the higher reading.

How to interpret the values

• An average of home readings ≥ 135/85 mmHg corresponds to high blood pressure (≥ 140/90 mmHg in the clinic).
• A single high value is not a diagnosis. What matters is the average and the trend over the days.
• The treatment target is set individually by the doctor; for most people who tolerate it, a systolic of 120–129 mmHg is aimed for.
• Very low blood pressure with dizziness or fainting should also be reported.

The most common mistakes

• measuring right after eating, coffee, smoking or walking
• legs crossed, back unsupported, talking
• the wrong cuff or over thick clothing
• a single reading, not repeated
• measuring every hour out of anxiety — this can raise both blood pressure and anxiety
• changing medicines based on a single reading

If your pulse is completely irregular (e.g. atrial fibrillation), many ordinary devices give less reliable values; ask your doctor.

The blood pressure diary

Record the date, time, values (systolic/diastolic), pulse and the medicines taken. Bring it to the visit or show a photo of the device. The doctor needs the 7-day average, not a single value.

Do not stop treatment because one reading came out normal — it is normal precisely because of the medicines. For more, see arterial hypertension.