Blood pressure readings are a key part of checking heart health, and they’re made up of two numbers: the top number, called systolic pressure, and the bottom number, called diastolic pressure. Systolic pressure measures how hard the heart pushes blood into the arteries, while diastolic pressure shows how much pressure remains in the arteries when the heart is resting between beats.
A new study from the University of Southern Denmark looked closely at which of these two numbers gives a better warning about heart problems—and found that it depends on your age.
For many years, doctors used both numbers to understand heart health. But more recently, most attention has shifted toward the systolic reading. That’s because higher systolic pressure is strongly linked to heart disease and early death, especially in older adults. However, this new study shows that the diastolic number shouldn’t be ignored, particularly for younger people.
Researchers followed the health records of more than 107,000 adults in Denmark over 26 years. When the study began, none of these individuals had heart disease.
Over time, some experienced heart-related events like heart attacks, strokes, or death due to heart conditions. By comparing the participants’ blood pressure readings with these outcomes, the scientists were able to see which numbers best predicted future problems.
They found that in people under the age of 50, diastolic blood pressure offered extra helpful information about their risk for heart disease. In other words, even if a younger person’s systolic pressure was normal, a high diastolic reading could still mean they were at risk.
On the other hand, systolic pressure remained a reliable warning sign for heart problems across all age groups, regardless of age, sex, or other risk factors.
The researchers also looked at another useful measure called mean arterial pressure or MAP. This number is calculated using both systolic and diastolic readings and gives an average blood pressure during a full heartbeat cycle. They found that MAP is a strong overall indicator of heart health risk for people of all ages.
These findings remind us that heart health isn’t one-size-fits-all. While systolic pressure may carry more weight overall, younger adults should still pay attention to their diastolic numbers. For people under 50, both numbers matter when it comes to spotting early warning signs.
High blood pressure is a common problem. According to the American Heart Association, nearly half of adults in the U.S. have high blood pressure—defined as 130/80 mmHg or higher. And it’s not just older adults who are affected. Data from the Centers for Disease Control and Prevention shows that more than 1 in 5 adults aged 18 to 39 also have high blood pressure.
This makes it especially important to raise awareness among younger adults. Many may not realize they are at risk, especially if they feel healthy or don’t get regular check-ups.
The study, led by Dr. Michael Hecht Olsen and published in the journal Hypertension, highlights the importance of tracking both systolic and diastolic pressure, as well as continuing research to improve how high blood pressure is managed.
It also supports the idea that personalized care—based on a person’s age and overall health—can help doctors better prevent heart disease and save lives.
As research continues, scientists are also exploring how lifestyle choices, such as diet and daily habits, affect blood pressure. For now, this study offers a valuable message: whether you’re young or old, understanding your blood pressure—and both numbers that come with it—can make a big difference in protecting your heart.
If you care about high blood pressure, please read studies that early time-restricted eating could help improve blood pressure, and natural coconut sugar could help reduce blood pressure and artery stiffness.
For more information about blood pressure, please see recent studies about added sugar in your diet linked to higher blood pressure, and results showing vitamin D could improve blood pressure in people with diabetes.
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