BIHS FAQs Frequently Asked Questions
The information on our website is mainly aimed at healthcare professionals. Patient information can be found on the Blood Pressure UK website.
We are unable to provide individual advice but Blood Pressure UK, set up especially for patients, provides information and support to people with high blood pressure.
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Blood Pressure Measurement
Click here for guidelines
If the first reading is 140/90 mmHg or higher, take another reading (with a minute interval between readings). If the second reading is very different to the first reading, take a third reading. If difference continues consider taking more readings. Record the lower of the last 2 readings as the clinic BP.
If you are using a manual blood pressure monitor, it is sensible to position the tubes to the top of the cuff so that they don't interfere with the stethoscope. If you are using an automatic device then it doesn't matter which way up you use the cuff. Some cuffs are conically shaped i.e. larger at the top than the bottom to fit the shape of the upper arm. In this case there is only one way to fit with tubes downwards.
The bladder which you will find inside the cuff should fit around at least 80% of the arm but not more than 100%. A cuff that does not fit properly will not give an accurate reading so it is important to use the right size. For cuffs with no obvious bladder follow the manufacturer’s instructions for when to use small, medium, large or extra-large cuff.
Contact the manufacturer of the blood pressure monitor. They may be able to supply an extra-large cuff. If the arm circumference is too large for any cuff then switch to manual measurement and ensure the centre of the bladder (which is inside the cuff) is placed over the brachial artery. This will give you the most accurate reading you can achieve under challenging circumstance. Be aware that because the cuff is too small it may overestimate the blood pressure. If a correctly fitting cuff cannot be fitted or is unavailable or cannot be applied then wrist blood pressure measurement, with the wrist held at the level of the heart, is the best alternative means of blood pressure measurement. See BIHS Statement on Diagnosis of BP in Obese Patients.
There are currently no published, formal guidelines for BP measurement in the leg. However, for practical advice, click here
Blood Pressure Monitors
There is a list of BIHS approved monitors on the website. Click here. The list is impartial so we are not able to make a specific recommendation.
The BIHS Blood Pressure Measurement Working Party will consider the report of a clinical validation study on a blood pressure monitor that has been published in a peer reviewed journal. If the study has been performed strictly in accordance with the BIHS Revised Protocol, the International Protocol (1 or 2) and the device has been shown to give accurate readings, then the Working Party will approve the device for inclusion in the list on the BIHS website. The Working Party reviews newly published papers on a regular basis but there will be some delay between the publication and a decision on whether or not to list the device.
Either the published report on a successful validation study is currently under review, the Working Party has not been satisfied that the protocol criteria have been strictly followed or, as far as the BIHS is aware, there has been no published report on a successful validation study performed on the monitor.
The manufacturer's recommendations should be followed.
Aneroid monitors can be used as long as they have been independently validated and are regularly calibrated (every 6 months) as they have a tendency to lose accuracy with use. Since 2015 Mercury sphygmomanometers can no longer be sold in the EU. They can still be used in on-going clinic trials and to validate blood pressure monitors.
No automatic blood pressure monitor has been independently validated for use in AF or with an irregular heartbeat. If the patient has an irregular pulse then you need to switch to using an independently validated manual blood pressure monitor. Many automatic blood pressure monitors detect an irregular heart beat (IHB). Some devices describes detecting atrial fibrillation. If an irregular heart beat/A fib is detected in any device then you need to switch to using a manual device and home BP monitoring is not recommended. AF would need to be confirmed with an ECG.
The patient should not use a home blood pressure monitor if they have AF or an irregular heart beat because it will give inaccurate results. Most people are able to tolerate 24-hour monitoring however when the blood pressure is particularly high >160/100 the repeated inflation to occlude this high pressure can cause petechial marking and at times puffiness in the hand which takes time to resolve- if this occurs the patient should be advised to stop the ABPM and can use the monitor to collect home readings in the usual way; 7 days readings, 3 morning and 3 evening, each 1 minute apart and commenced after 10mins seated rest. Reading 1 and 2 are recorded and they can ask for a record sheet and activity diary. The use of arm in case of prior breast / lymph node surgery and or presence of venous fistula or similar should be avoided. ABPM monitoring for some is stressful and it increases their blood pressure which defeats the point as we are trying to establish a 'true' BP. If they are likely to find the ABPM stressful HBPM is often a better option as the patient remains in control and can aim to rest and relax at the morning and evening intervals when manually recording their BP. The patient must not drive whilst wearing an ABPM as it will affect their car insurance.