High blood pressure, also known as hypertension, is one of the most common health conditions worldwide.
It affects billions of people and is a major cause of heart attacks, strokes, heart failure, kidney disease, and premature death.
Because high blood pressure often causes no symptoms, many people do not realize they have it until serious health problems develop.
Doctors measure blood pressure using two numbers. The first number, called systolic blood pressure, measures the pressure inside the arteries when the heart pumps blood around the body. The second number, known as diastolic blood pressure, measures the pressure in the arteries when the heart relaxes between heartbeats.
For example, if a person’s blood pressure is 120 over 80, the systolic pressure is 120 and the diastolic pressure is 80.
For many years, doctors believed that lowering blood pressure too much could be risky, especially if the diastolic number dropped below 70.
Some experts worried that very low diastolic pressure might reduce blood flow to important organs, including the heart itself. Because of this concern, physicians often tried to lower blood pressure carefully while avoiding excessive reductions in the diastolic number.
However, a new international study is challenging this long-standing belief.
Researchers from the National University of Ireland Galway, now known as the University of Galway, together with collaborators from other institutions, analyzed health information from more than 47,000 people around the world.
Their findings suggest that low diastolic blood pressure may not be as dangerous as previously thought for people with high blood pressure.
The study was led by Professor Bill McEvoy and was published in the journal Circulation.
The researchers carefully examined the relationship between blood pressure levels and the risk of cardiovascular disease. They wanted to determine whether low diastolic pressure itself increases the risk of heart problems or whether other factors are more important.
Their analysis found no evidence that diastolic blood pressure below 70 directly causes harm in people being treated for high blood pressure. This finding challenges years of medical thinking and may influence future treatment recommendations.
At the same time, the study confirmed something that many experts have suspected for years: systolic blood pressure appears to be a stronger predictor of heart disease and stroke risk.
The researchers found that systolic pressure above 120 was associated with a higher risk of cardiovascular problems. In other words, the top number may be more important than the bottom number when it comes to protecting long-term heart health.
These findings could have important implications for the treatment of hypertension. Doctors may be able to focus more aggressively on lowering systolic blood pressure into a healthier range without becoming overly concerned if diastolic pressure falls somewhat lower than previously recommended.
According to the study, a systolic blood pressure between about 100 and 130 may offer benefits for many patients. If future research confirms these findings, healthcare providers may feel more comfortable aiming for lower systolic targets when treating high blood pressure.
The results are especially important because high blood pressure remains one of the leading causes of preventable illness and death worldwide. Better treatment strategies could help reduce the number of heart attacks, strokes, and other cardiovascular complications.
While medications play an important role in controlling blood pressure, experts continue to emphasize that healthy lifestyle habits are equally important.
Maintaining a healthy weight is one of the most effective ways to reduce blood pressure. Excess body weight forces the heart to work harder and places additional stress on blood vessels. Even modest weight loss can lead to meaningful improvements in blood pressure levels.
Diet also plays a major role. Eating plenty of fruits, vegetables, whole grains, lean proteins, and low-fat dairy products can support healthy blood pressure. Many experts recommend eating patterns such as the Mediterranean diet, which focuses on natural foods and healthy fats while limiting processed products.
Reducing salt intake is another important step. Excess sodium causes the body to retain water, which increases pressure inside blood vessels. Most health organizations recommend limiting sodium intake to no more than 2,300 milligrams per day, and some people may benefit from even lower amounts.
Regular physical activity can also make a significant difference. Activities such as walking, cycling, swimming, and other moderate exercises strengthen the heart and improve circulation. Most adults are encouraged to aim for at least 150 minutes of moderate exercise each week.
Limiting alcohol consumption is also important. Excessive drinking can increase blood pressure and contribute to other health problems. Healthcare guidelines generally recommend moderation, with lower limits for women than for men.
Smoking remains one of the most damaging habits for cardiovascular health. Tobacco damages blood vessels, accelerates the development of artery disease, and increases the risk of heart attacks and strokes. Quitting smoking provides major benefits at any age.
Managing stress may also help. While temporary stress causes short-term increases in blood pressure, long-term stress may contribute to ongoing hypertension in some people. Relaxation techniques such as meditation, deep breathing exercises, yoga, and mindfulness practices can support overall cardiovascular health.
Regular monitoring remains essential because high blood pressure often develops silently. Routine blood pressure checks at home or during medical appointments can help identify problems early and allow treatment to begin before serious complications occur.
The new study provides reassuring evidence that low diastolic blood pressure may not be the danger it was once thought to be. Instead, the findings suggest that controlling systolic blood pressure may deserve greater attention when treating hypertension.
Although more research will continue to refine blood pressure targets, the study offers valuable information for doctors and patients alike. By focusing on effective treatment and maintaining healthy lifestyle habits, people can significantly reduce their risk of heart disease, stroke, and other complications associated with high blood pressure.
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 How to eat your way to healthy blood pressure and results showing that Modified traditional Chinese cuisine can lower blood pressure.
The study was published in the journal Circulation.
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