This guide is intended to provide the basic knowledge necessary to successfully carry out home blood pressure monitoring.
Before undertaking home blood pressure measurement, it is important to have some understanding of what is meant by high blood pressure and the role of home blood pressure monitoring in managing the condition.
- What is blood pressure?
- What is high blood pressure?
- What is a target blood pressure?
- Who should monitor blood pressure at home?
- What blood pressure device should I use?
- How to do I measure blood pressure?
- How should I record my blood pressure measurements?
- When do I need to be reviewed by a health care professional?
Your heart pumps blood around the body through the arteries by contracting and relaxing. Blood pressure, is the pressure of blood flowing through the arteries and varies at different times in the heartbeat cycle.
A person’s blood pressure is expressed as follows systolic / diastolic – e.g. 117/79
- Systolic blood pressure is the peak blood pressure when the heart muscle contracts forcing blood around the body.
- Diastolic blood pressure is the trough blood pressure when the heart muscle is relaxed between heart beats.
So a blood pressure of 117/79 means systolic blood pressure of 117 mmHg and diastolic blood pressure of 79 mmHg.
We call high blood pressure ‘hypertension’ and we grade the severity of hypertension depending on the blood pressure level.
Home blood pressure readings are generally lower than clinic readings, so consistent home blood pressure readings above 135/85 is regarded as high. Clinic readings are generally 5mmHg higher so a comparable surgery reading would be 140/90.
Based on consistent home blood pressure measurements, high blood pressure can be graded as follows:
- Stage 1 hypertension – blood pressure in the range 135 to 155/85 to 95.
- Stage 2 hypertension – blood pressure in the range 156 to 175/86 to 105.
- Stage 3 hypertension – blood pressure above 175/105.
Please remember that blood pressure will vary throughout the day and from day to day, so it is important to take a series of readings over several days to determine if blood pressure is genuinely increased.
If your blood pressure is 175/105 or above i.e. stage 3 hypertension, measure blood pressure again after a couple of hours, if the blood pressure remains the same, contact the surgery and request a same day appointment with your nurse or GP.
Target blood pressure is the blood pressure level your doctor feels is most appropriate for your particular circumstances.
Your doctor will consider many factors when recommending a target blood pressure including the response and tolerance to medication. Target blood pressure is determined on an individual basis.
The following list provides some general guidance:
- For the general adult population target blood pressure is 135/85 or below.
- If you have a diagnosis of hypertension the target blood pressure is 135/75 or below.
- If you have a diagnosis of diabetes or kidney disease, the target blood pressure is 125/75 or below.
- Individual target blood pressure may be set depending on your response and ability to tolerate medication to bring down your blood pressure. Your doctor will advise you.
Anyone can measure blood pressure as part of their health care regime provided doing so does not cause unnecessary anxiety. Checking your own blood pressure periodically will help you identify if you are one of the many people with undiagnosed hypertension. Blood pressure tends to increase with age, so checking blood pressure becomes more relevant as we get older.
If you have diabetes, high blood pressure, chronic kidney disease or heart disease home blood pressure monitoring is particularly useful. If you have one of these conditions, checking your own blood pressure at home will give your the freedom to monitor the effectiveness of treatment and prompt you to consult your health care professional if your blood pressure is not properly controlled. Monitoring blood pressure will result in improved blood pressure control and reduce the risk of complications occurring.
It is important to remember that blood pressure in children, young adults and pregnant women is normally low, so home blood pressure monitoring in these groups is not generally advisable unless recommended by your doctor.
It is important to only use a device approved for use in the United Kingdom.
The British Hypertension Society publish a list of devices approved for use for home blood pressure monitoring.
It is important to choose a device with an appropriate cuff size. Using a cuff that is too small or large will result in unreliable blood pressure readings. Your local pharmacist will also be able to offer advice.
Provided you are using a device approved for use in the United Kingdom with a correct sized cuff, blood pressure measurements should be as accurate as those obtained by your doctor or nurse.
Blood pressure devices are calibrated when they leave the factory but, can lose accuracy with time. It is important for the accuracy of your blood pressure device to be checked annually by comparison with a calibrated surgery device for your blood pressure to be monitored safely.
Home blood pressure devices are reliable provided they are used correctly. Always refer to the manufacturers instructions before measuring your blood pressure.
These simple tips will help to check your blood pressure correctly:
- Avoid taking blood pressure within 30 minutes of eating, exercising, taking a bath or drinking alcohol.
- Make sure that you have plenty of time and feel relaxed. Sit for at least 5 minutes with your feet on the floor before taking blood pressure. If you are in a hurry or feel anxious your blood pressure will be raised and measuring blood pressure will make you worry unnecessarily.
- Only use an approved ARM device to measure blood pressure. We do not recommend the use of wrist devices.
- Make sure that the cuff is the correct size and positioned correctly, refer to the manufacturers instructions for guidance.
- Position your arm so that the cuff is level with your heart.
- Inflate the cuff by pressing the start button on the device.
- Each time you measure blood pressure take a minimum of three readings separated by at least one minute. If necessary, take additional readings until you obtain consistent results.
- Check your blood pressure in the morning and evening, pick a time when you have time to relax. Try and take blood pressure at the same time in the morning and evening each day.
It is important not to allow measuring your own blood pressure to make you worry unnecessarily, so avoid taking blood pressure too frequently. The following information will help you decide how often to check your blood pressure.
- If you are just checking your blood pressure as part of your health regime, checking your blood pressure a couple of times a year is fine. It is not a good idea to repeatedly check your blood pressure, this will only cause unnecessary worry.
- If you have hypertension, diabetes, heart disease, stroke or kidney disease your doctor will advise you about your target blood pressure:
- Provided your blood pressure does not exceed your target blood pressure, you should continue to check your blood pressure on one day every three months, taking a series of three morning and evening measurements. Checking your blood pressure before any scheduled visits to see your doctor would be a good time – don’t forget to take a record of your measurements whenever you attend the surgery.
- If your blood pressure exceeds your target blood pressure, more frequent testing is advisable – check your blood pressure on 3 separate days over a 7 day period, ensuring to check the blood pressure on days when you are not unduly stressed. Make a record of your readings and arrange a telephone consultation with your practice nurse or doctor.
- If blood pressure is significantly elevated, 175/105 mmHg or above, you should request urgent review with your GP to review your medication.
We recommend keeping a written record of blood pressure readings and to help you we have made a blood pressure record sheet available for download. Having a written record of blood pressure will help you discuss blood pressure management with your health care professionals.
|Personal blood pressure record sheet:|
The practice would like patients to take more responsibility for monitoring their own blood pressure but, this does not mean that you no longer require review by a health care professional.
- Patients taking medication will be provided with a written treatment protocol detailing target blood pressure, side effects of prescribed medication and information when scheduled review by a health care professional is required.
- All patients with hypertension require as a minimum, an annual review by a health care professional. Annual review is a face to face consultation with your practice nurse or health care assistant when monitoring blood tests can be arranged and the accuracy of the home blood pressure monitoring device checked.
- Patients with blood pressure above target level require more frequent intervention to enable blood pressure medication to be adjusted until target blood pressure is achieved. In the majority of cases, there will be no need for a face to face consultation, a telephone consultation can be arranged to discuss any changes with your GP or practice nurse.
- Patients taking medication require periodic blood tests to monitor for any adverse effects. Blood tests are normally required annually and more frequently when the dose of some medications are being used.
- In addition to schedule review(s) arranged by the practice, patients monitoring their own blood pressure should act on blood pressure measurements that are above their target blood pressure. Review can be arranged by requesting a telephone consultation with your GP or practice nurse.
- Blood pressure readings indicating stage 3 hypertension i.e.175/105 mmHg or above should prompt you to request a same day GP appointment to have treatment reviewed.