Ambulatory Blood Pressure Monitoring (ABPM)

ABPM is a 24-hour automatic blood pressure recording technique. A cuff on your upper arm inflates automatically every 20–30 minutes during the day and every 30–60 minutes at night, recording 50–70 BP readings. This provides a complete picture of your blood pressure across all activities — work, meals, exercise, sleep — revealing patterns that a single clinic reading cannot show, including white-coat hypertension, masked hypertension, and nocturnal non-dipping.

White-coat hypertension occurs when blood pressure is elevated in the clinic (≥140/90 mmHg) but normal in daily life on ABPM (24-hour average <130/80 mmHg). The elevated clinic reading is caused by anxiety and the alerting response to the clinical environment. It affects approximately 20–30% of patients diagnosed with hypertension by clinic measurement alone. True white-coat hypertension typically does not require antihypertensive medication — confirming it with ABPM avoids unnecessary treatment.

Masked hypertension is the opposite of white-coat hypertension — clinic BP appears normal (below 140/90 mmHg) but ABPM reveals elevated blood pressure during daily activities. It affects approximately 15–20% of people with apparently normal clinic BP. Masked hypertension carries the same cardiovascular risk as sustained hypertension and is completely undetectable without ABPM. It is particularly important to detect in patients with diabetes, chronic kidney disease, or a strong family history of heart disease despite normal clinic readings.

Nocturnal dipping is the normal physiological fall in blood pressure during sleep — typically more than 10% below daytime values. This overnight recovery period is important for cardiovascular health. Non-dipping (BP falls less than 10% at night) and reverse dipping (night BP higher than day) are abnormal patterns strongly associated with heart attack, stroke, left ventricular hypertrophy, and kidney disease — even when average 24-hour BP appears controlled. ABPM is the only investigation that assesses nocturnal dipping and this important cardiovascular risk marker.

No, the ABPM monitor and cuff assembly are not waterproof. You should avoid showering, bathing, or swimming during the 24-hour recording period. Sponge baths are acceptable, taking care not to wet the cuff or recording console. We recommend showering immediately before your appointment for fitting, as you will not be able to do so again until the device is removed the next morning.

The ABPM device is designed to be as unobtrusive as possible. The cuff inflation feels similar to a standard BP check at the doctor's office. Some patients report brief sleep disruption from night-time inflations, but the device is calibrated to minimise disturbance. The clinical value of nocturnal BP data — especially the dipping pattern — far outweighs any mild inconvenience. Most patients tolerate the monitor very well and sleep through inflations after the first night.

Home BP monitoring involves self-measured readings taken manually at specific times, which is useful for tracking trends but cannot capture night-time BP or the full circadian profile. ABPM is recommended when there is suspicion of white-coat hypertension, masked hypertension, nocturnal non-dipping, or resistant hypertension. ABPM is also indicated when home readings are inconsistent or when accurate 24-hour BP load assessment is needed for treatment decisions. Your cardiologist will advise which method suits your clinical profile.

A non-dipper pattern — where BP falls less than 10% during sleep — indicates increased cardiovascular and renal risk. If ABPM reveals non-dipping, your cardiologist may recommend shifting some or all of your antihypertensive medications to evening dosing (chronotherapy). The MAPEC and Hygia Chronotherapy Trials demonstrated that bedtime dosing significantly reduces cardiovascular events compared to morning dosing in non-dipper patients. This is a key advantage of ABPM-guided personalised therapy.