Blood pressure is measured in two numbers: the top number (systolic blood pressure) over the bottom number (diastolic blood pressure). When these numbers are higher than normal, you have high blood pressure (hypertension). But what’s more important, systolic or diastolic blood pressure? And what if your systolic blood pressure is high and your diastolic blood pressure is normal?
This guide will, we’ll explain more about systolic blood pressure and isolated systolic hypertension (ISH), together with the causes and treatments, including the lifestyle changes you can make to help reduce systolic blood pressure.
You probably already know the difference between systolic and diastolic blood pressure. Systolic pressure is the force the heart uses to pump blood out to the body; diastolic pressure is the pressure in your blood vessels between beats.
Both numbers in your blood pressure reading are equally important when it comes to diagnosing and treating hypertension. However, as Harvard Medical School confirms, most studies show that a high systolic blood pressure carries a greater risk of stroke and heart disease than elevated diastolic pressures, especially in people over 50.
Here’s how to understand your systolic blood pressure number:
Normal | Below 120 |
Elevated | 120-129 |
Stage 1 hypertension | 130-139 |
Stage 2 hypertension | 140 or more |
Hypertensive crisis | 180 or more |
Isolated systolic hypertension (ISH) is when you have a high systolic blood pressure reading (140 or higher) and a normal diastolic blood pressure reading (less than 80). Even though only one number is elevated, ISH is still considered a type of high blood pressure. It’s actually the most common type of high blood pressure in people aged 65 and over.
Like other types of high blood pressure, ISH can increase the risk of a range of health conditions, including heart attack, stroke, kidney disease and heart failure.
There’s often no identifiable cause of isolated systolic hypertension other than simply getting older. As we age, the arteries become less elastic. They may also become stiffer due to fatty deposits on the artery wall, known as plaque.
Sometimes, ISH is developed as a result of another medical condition affecting the circulatory system. These include:
You may also be more likely to develop ISH if:
Like other forms of high blood pressure, the key to treating ISH is a sensible combination of lifestyle changes, medication, or both. If an underlying condition is causing or contributing to ISH, your doctor will work to treat that as well.
Your doctor will let you know whether medication to lower systolic blood pressure is a good option for you. Either way, they’ll likely advise you to make a few lifestyle changes to help manage the condition and improve your general health. These may include:
High blood pressure is known as ‘the silent killer’ because it typically has no symptoms or warning signs. The only way to know whether your blood pressure is too high is to get it measured when you visit your GP, at a pharmacy, or at home, with a home blood pressure monitor.
Understanding your blood pressure and monitoring changes is an important step towards taking control of your health. You might want to take a look at our guide, how to use a blood pressure monitor as well as our Blood Pressure Monitor Buying Guide.