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Do you know your numbers?

Updated: Sep 6, 2022

This week is national 'Know Your Numbers!' week, a Blood Pressure UK initiative that raises awareness of high blood pressure and encourages all UK adults to get their blood pressure checked. When did you last check yours?

Why get your blood pressure checked?

A healthy blood pressure is critical to long-term health and disease prevention, but many UK adults do not regularly have their blood pressure checked and are therefore at risk of undiagnosed high blood pressure and its many complications.

High blood pressure rarely has noticeable symptoms, but if left untreated leads to serious diseases such as stroke and heart attack. For this reason, high blood pressure is often referred to as a ‘silent killer’. The only way to detect high blood pressure is by having a blood pressure reading taken, ideally by a trained health professional.

High blood pressure is very common

1 in 3 adults in the UK have high blood pressure, and a staggering 1 in 2 don’t know they have it or aren’t receiving treatment for it. That’s an estimated 6 million UK adults living with undiagnosed high blood pressure! [1]

High blood pressure leads to serious, preventable illness

High blood pressure is implicated in 50% of all heart attacks and strokes, and is a leading cause of kidney failure, heart failure, peripheral arterial disease, vascular dementia and visual problems [2]. Every day around 350 people in the UK have a stroke or heart attack associated with high blood pressure that could have been prevented, and high blood pressure is estimated to cost the NHS £2.1 billion every year [3].

What causes high blood pressure?

High blood pressure (hypertension) doesn’t always have a clearly identifiable cause. Most people diagnosed will have ‘primary hypertension’, hypertension without a specific cause but often linked to lifestyle factors (below). A small minority of cases will have a clearly identifiable cause, most often a medical condition, such as certain kidney or endocrine (hormonal) disorders [4].

However, there are known risk factors for developing high blood pressure, many of which are ‘modifiable’ and therefore preventable. These include:

- Excessive alcohol consumption

- Smoking

- Obesity

- Lack of physical activity

- Excessive salt intake

- Poor sleep

In addition, high blood pressure is more common in people over the age of 65, those with a family history, people of black African or black Caribbean descent and those living in deprived areas. However, even in these instances, blood pressure can usually be improved by changes to diet and lifestyle [2][5].

Understanding blood pressure readings

A blood pressure reading contains two numbers, a top number representing ‘systolic’ pressure and a bottom number representing ‘diastolic’ pressure. The systolic pressure is the pressure inside the arteries when the heart muscle contracts, and the diastolic pressure is the pressure in the arteries between contractions (heartbeats), when the heart muscle relaxes. Blood pressure is measured in mmHg (millimetres of mercury), as historically, blood pressure measuring devices contained a column of mercury that moved according to pressure.

When read together, the systolic and diastolic blood pressures provide a useful overall measurement of blood pressure. However, clinicians may also consider the two pressures in isolation because variations in each can be indicative of certain cardiovascular problems. For example, an isolated systolic hypertension may suggest that arteries are excessively stiffened, possibly due to plaque build-up or other condition that damages artery walls, such as poorly controlled diabetes or anaemia. Conversely, an isolated diastolic hypertension can be associated with an increased risk of adverse cardiovascular events, such as a heart attack, particularly in younger patients. Ultimately, your clinician will consider these factors in the context of your overall health, before deciding on the most appropriate course of action.

Diagnosing high blood pressure