High blood pressure, or hypertension, is extremely common and often causes no obvious symptoms.
Over time, however, the extra pressure can damage blood vessels and place more strain on the heart. This raises the risk of heart attack, stroke, kidney disease, and other serious health problems.
A blood pressure reading contains two numbers. The upper number is systolic blood pressure, which measures pressure in the arteries when the heart contracts and pumps blood.
The lower number is diastolic blood pressure, which measures pressure while the heart relaxes between beats.
For many years, doctors paid close attention to both numbers when treating hypertension. There was particular concern about allowing diastolic pressure to fall too far, because the heart receives much of its own blood supply while it is relaxing. Some experts worried that very low diastolic pressure could reduce blood flow to the heart and increase health risks.
Research led by scientists at NUI Galway, now the University of Galway, challenged this concern. The study was published in Circulation, a journal of the American Heart Association. Researchers examined information from more than 47,000 people involved in major blood pressure studies.
The researchers wanted to understand whether people were harmed when treatment lowered their diastolic blood pressure below levels that doctors had traditionally considered comfortable. Their analysis found no clear evidence that a diastolic pressure below 70 mm Hg caused additional harm when systolic blood pressure was being successfully controlled.
Instead, the upper number appeared to be especially important. Higher systolic blood pressure was linked to greater risks of cardiovascular problems, including heart attack and stroke. The findings supported concentrating on bringing systolic pressure into a healthy range rather than avoiding treatment simply because the lower number becomes relatively low.
The researchers suggested that a systolic blood pressure between about 100 and 130 mm Hg may be a reasonable range for many people receiving treatment. This does not mean that everyone should try to reach exactly the same number. Age, medical history, medications, symptoms, and other health conditions can affect the safest target for an individual.
The study may help doctors make treatment decisions with greater confidence. A person whose systolic pressure remains high may still benefit from treatment even if there is concern that the diastolic number could fall below 70. However, medication changes should always be discussed with a health professional rather than made based on a single reading.
Blood pressure can also change throughout the day. Stress, exercise, caffeine, illness, sleep, and even the way a person sits during a measurement can affect the result. Doctors therefore often use repeated readings, including measurements taken at home, before making important treatment decisions.
Medication is only one part of blood pressure management. Regular physical activity, maintaining a healthy weight, eating a nutritious diet, and reducing excess salt can all help lower blood pressure. Not smoking and limiting alcohol can also reduce the risk of heart and blood vessel disease.
These habits are important because hypertension can quietly damage the body for years. Many people discover that they have high blood pressure only during a routine medical visit. Regular checks are therefore especially valuable for adults who have other risk factors for heart disease.
The Circulation study changes an important part of the discussion about hypertension treatment. Rather than becoming overly concerned about a lower diastolic reading, doctors may be able to place greater emphasis on safely controlling high systolic pressure.
For patients, the main message is not to chase a particular number alone, but to work with a health professional to find a blood pressure target that fits their overall health.
If you care about high blood pressure, please read studies about vitamins impacts on high blood pressure people need to know, and how to manage high blood pressure and diabetes with healthy foods.
For more health information, please see recent studies about the best and worst foods for high blood pressure, and modified traditional Chinese cuisine can lower blood pressure.
Copyright © 2026 Knowridge Science Report. All rights reserved
