One of the problems with automated blood pressure monitors is that they are too accurate. They can hit the difference of the space between beats (between the two blue stars). See an excellent video explaining this here. Therefore you need to recheck the reading at least three times.
This can account for a considerable difference in readings and is often the reason why GPs and paramedics who are using spirometers think these machines are faulty. Mostly they are not though non-medical people often fail to have their machines recalibrated by the manufacturer every year. Paaramedics tend to use Wright's aneroid manometers (below left) which aren't so specific and, much like the old fashioned mercury machines in a metal box that has to be used with a stethoscope (below right), the number can be 'grabbed' from the dial as the needle descends. Therefore (I argue!) it is actually less accurate than a digital machine.
Another factor is your position when taking BP. The arm should be almost level with the heart and supported on a table or chair arm and relaxed. Some would also say that the patient needs to be seated and not talking for 5 minutes before recording the blood pressure and have neither smoked nor partaken of alcoholic drinks.
As for the numbers, ideally, we should all have a blood pressure below 120 over 80 (120/80). When I started out in OH, the numbers were considered to be acceptable provided it was 100+the patient's age and under 100 or 2 digits. Over the years it has been reduced and reduced until now (2010), it is only considered safe if the systolic is <120 and the diastolic is <80.
This can account for a considerable difference in readings and is often the reason why GPs and paramedics who are using spirometers think these machines are faulty. Mostly they are not though non-medical people often fail to have their machines recalibrated by the manufacturer every year. Paaramedics tend to use Wright's aneroid manometers (below left) which aren't so specific and, much like the old fashioned mercury machines in a metal box that has to be used with a stethoscope (below right), the number can be 'grabbed' from the dial as the needle descends. Therefore (I argue!) it is actually less accurate than a digital machine.
Another factor is your position when taking BP. The arm should be almost level with the heart and supported on a table or chair arm and relaxed. Some would also say that the patient needs to be seated and not talking for 5 minutes before recording the blood pressure and have neither smoked nor partaken of alcoholic drinks.
As for the numbers, ideally, we should all have a blood pressure below 120 over 80 (120/80). When I started out in OH, the numbers were considered to be acceptable provided it was 100+the patient's age and under 100 or 2 digits. Over the years it has been reduced and reduced until now (2010), it is only considered safe if the systolic is <120 and the diastolic is <80.