What is 24-48 Hour Blood Pressure Monitoring?
A 24-hour or 48-hour blood pressure monitoring, also known as 24-hour or 48-hour ambulatory blood pressure monitoring (ABPM), is a method to measure and record your blood pressure (BP) over a 24- or 48-hour period during your normal daily routine. It is one of the best ways to monitor your blood pressure because it means you can go on with your normal activities as usual. As our blood pressure does not always remain the same and varies depending on our actions and state of mind, 24- to 48-hour ambulatory BP monitoring assists physicians to analyse an individual’s BP status approximately every 20 minutes over a 24-hour or 48-hour period utilising a cuff on your arm, which is connected to a portable monitor worn on your waist. This consistent monitoring provides your physician with a detailed picture of how your blood pressure changes over the course of a day or two and will assist them to work out the most effective medication for you if you have high blood pressure (hypertension).
Indications for 24-48 Hour Blood Pressure Monitoring
Your physician may recommend 24-hour or 48-hour blood pressure monitoring to individuals suffering from high blood pressure.
Blood pressure (BP) or hypertension is the pressure exerted by blood against the artery walls each time the heart beats. It is measured as systolic and diastolic pressures, i.e., blood pressure when the heart beats, and blood pressure in between beats, when the heart is at rest. Normal BP is ≤120 (systolic blood pressure)/80 (diastolic blood pressure) mmHg. High blood pressure is a condition that occurs when the pressure of blood in the blood vessels is ≥140/90 mmHg.
High blood pressure can go unnoticed for years, during which time it can damage your blood vessels, heart, kidneys, and other organs. It can, in turn, lead to major health risks such as heart attacks, kidney failure, blindness, stroke, and coronary heart diseases. A 24-48 hour ambulatory blood pressure monitoring can help detect abnormal changes in BP that might otherwise go unnoticed.
In general, physicians use 24-hour or 48-hour blood pressure monitoring for many reasons, including to:
- Confirm the diagnosis of hypertension
- Identify how changes in your blood pressure relate to your sleep patterns and daily activities
- Identify changes in your blood pressure readings at home, rather than at your healthcare provider’s office
- Know how effectively your blood pressure medication is managing your high BP
Types of Hypertension
A 24-48 hour ambulatory blood pressure monitoring is a useful method to detect several types of blood pressure patterns, such as:
- White coat hypertension: This term refers to individuals who have normal blood pressure at home but elevated blood pressure in a healthcare setting.
- Masked hypertension: This term refers to individuals whose blood pressure is normal at their healthcare provider’s office but elevated at home.
- Sustained hypertension: This type refers to blood pressure readings that are elevated whether you are at home or in your provider’s office.
- Nocturnal hypertension: This refers to individuals whose blood pressure is elevated when asleep. This type of hypertension is more common among individuals who have kidney disease or diabetes.
Preparation for 24-48 Hour Blood Pressure Monitoring
Your healthcare provider will give you a series of tips to be followed prior to placement of the 24-48 hour blood pressure monitoring device. These include:
- Keep a diary to document your activities in a 24-hour period, such as your bedtime and wake-up time, meal times, and the time you take your medications. You should also document any symptoms you experience such as shortness of breath or dizziness.
- Choose a 24-hour period that best represents your usual routine. This preferably should be a weekday rather than a weekend.
- Avoid certain activities in your 24-hour period such as showering or swimming, strenuous physical activity, or removing any part of the BP monitoring device without notifying your healthcare provider.
Placement and Function of 24-48 Hour Blood Pressure Monitoring
Ambulatory blood pressure monitoring device placement takes place in your provider’s office. Before placement, your provider will usually review your history of high blood pressure and check your blood pressure manually once. Then, your provider fits you with a blood pressure cuff that is wrapped around the arm and is connected to a small device or equipment that resembles a portable radio on a strap or belt worn on your body for 24 to 48 hours. The monitoring device is set up to automatically measure your blood pressure at regular intervals throughout the day so that your average blood pressure can be calculated. The device periodically inflates and takes blood pressure measurements, while you do your normal daily activities and while you sleep, which are recorded for later printout and analysis. You can carry on with all your normal daily activities apart from swimming or bathing while you are wearing this device.
Results and Analysis
After placement of the device and giving appropriate instructions on the management of the device, your provider will send you home and ask you to document your blood pressure readings in a journal while engaged in different activities during your daily routine. A high blood pressure diagnosis will be made if your average home or daytime ambulatory blood pressure is 135/85mmHg or above. If your blood pressure is noted to be high your provider will decide if medication is proper in the circumstances and will also provide tips about lifestyle changes that can assist you in better management of your blood pressure. Cutting down on salt and doing more physical activity is beneficial and if you are overweight, losing some weight can also be beneficial.