New research from NUI Galway and other institutions has challenged an old idea about blood pressure.
For years, doctors worried that lowering the bottom number in a blood pressure reading—called diastolic pressure—too much could be dangerous.
But this new study shows that lowering diastolic pressure, even to levels once thought to be too low, may not cause harm at all.
This discovery is important because it may change the way high blood pressure is treated around the world. High blood pressure, also known as hypertension, is a major health problem.
It affects millions of people and increases the risk of heart attacks, strokes, kidney disease, and other health issues. It also puts people at higher risk for severe illness from infections like COVID-19.
In the past, doctors were careful not to lower diastolic blood pressure below 70 to 90 mmHg. They believed that going too low might increase the chances of heart problems.
But this new study looked at health data and genetic information from over 47,000 people across five different groups. The average age of the people in the study was 60 years.
What the researchers found was surprising. Even when a person’s diastolic pressure went as low as 50 mmHg, there was no sign that their risk of heart disease increased. This goes against the long-held belief that very low diastolic pressure is harmful.
The study was led by Dr. Bill McEvoy and published in the journal Circulation. It also confirmed something that scientists already knew: high systolic blood pressure—the top number in a reading—is still a major risk factor for heart disease and stroke.
People with systolic pressure over 120 mmHg are more likely to suffer from these serious health problems.
So, what does this mean for treatment? For years, many doctors hesitated to treat high systolic blood pressure too aggressively because they were afraid it would cause diastolic pressure to drop too low.
But now, the study suggests that the real focus should be on lowering systolic pressure to somewhere between 100 and 130 mmHg. This should be done even if it means the diastolic number goes below 70 mmHg.
The researchers believe this new information will help doctors better manage high blood pressure and keep more patients safe from heart disease and stroke. They hope the findings will lead to updated guidelines that allow doctors to treat systolic pressure more confidently, without worrying so much about the diastolic number.
In short, this study gives doctors new freedom to focus on what really matters—getting the top blood pressure number under control. That change could save lives and improve care for millions of people living with high blood pressure.
If you care about blood pressure, please read studies about high blood pressure treatment: ARBs vs. ACE inhibitors and blood pressure response to exercise can predict future heart disease.
For more about blood pressure, please read studies about This daily food is very important for blood pressure and heart health and Common blood pressure medication may have harmful side effects.
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