The NHS has issued a new warning urging people to check their blood pressure as part of its Know Your Numbers campaign, saying millions of adults could be putting their health at risk. In a social media post on Wednesday, September 9, the health service said: "Do you know what your blood pressure numbers mean? Find out this #KnowYourNumbers week! If you've checked your blood pressure, use our online tool to understand what your reading means and what you can do next."
Five-year rule
People aged 40 and over who have not had their blood pressure checked for more than five years are advised to get it tested. The warning comes because high blood pressure often causes no obvious symptoms, meaning people can have the condition without realising it.
NHS England estimates that around 4.1 million people in England are living with high blood pressure without knowing it. It has described the condition as a 'silent killer' because it can cause serious damage without necessarily making someone feel ill.
If left untreated, high blood pressure puts extra strain on the heart and blood vessels and can increase the risk of heart disease, heart attacks, strokes, heart failure and kidney disease.
What the numbers mean
The NHS has highlighted its online blood pressure checker, which allows people to enter a recent reading and find out what it means and what they should do next. A blood pressure reading is made up of two figures. The first, or systolic, number measures the pressure when the heart pumps blood around the body. The second, or diastolic, number measures the pressure when the heart relaxes between beats.
For example, a reading of 130/80 means a systolic pressure of 130 and a diastolic pressure of 80. As a general guide, the NHS considers blood pressure to be high when it is 140/90 or above when checked by a healthcare professional, or 135/85 or above when measured at home.
A reading below 120/80 is generally regarded as being in the healthy range, although blood pressure varies between people and throughout the day. A single high reading does not necessarily mean someone has hypertension.
If a clinic reading is 140/90 or above, NICE guidance recommends further monitoring, usually with a 24-hour ambulatory monitor or home blood pressure checks, to confirm whether the pressure remains high.
Where to get checked
The NHS says people can get their blood pressure checked at their GP surgery, while many pharmacies offer free checks to people aged 40 and over in England. It is also possible to monitor blood pressure at home using a suitable machine.
When taking a reading at home, the NHS recommends sitting upright with your feet flat on the floor, resting your arm on a table and relaxing without talking during the test. It advises taking a second reading a few minutes after the first to help make sure the result is accurate. The NHS says people should speak to their GP practice if they regularly use a home blood pressure monitor.
The latest push to get people checking their numbers comes after interest in NHS advice on high blood pressure surged. The NHS said its high blood pressure webpage received just over two million visits in 2025, up 36% on the previous year.
The message from health officials is simple: do not wait until you feel unwell. High blood pressure usually has no symptoms, which means checking the numbers may be the only way to discover there is a problem.
The NHS advises people who are worried about symptoms such as recurring headaches, blurred vision or chest pain to seek medical advice rather than relying on the online blood pressure checker. And anyone with new symptoms such as dizziness, nausea, headache or chest pain should not use the online tool as a diagnostic test and should instead seek appropriate medical help.
