A new study suggests that middle-aged adults whose blood pressure changes a lot over time may face a much higher risk of sudden cardiac death later in life.
Researchers found that people with the largest swings in blood pressure had up to a 70% greater risk of dying suddenly from heart-related problems compared to people whose blood pressure stayed more stable.
The findings were presented at the American Heart Association’s Scientific Sessions in Chicago. Although the research is still considered early and more studies are needed to confirm the results, scientists say the study highlights an important message: keeping blood pressure stable may be just as important as keeping it within a healthy range.
Most people think of blood pressure as a single number checked during a doctor’s visit. However, blood pressure naturally changes throughout the day and over the years. Stress, physical activity, sleep, medications, diet, illness, and emotional health can all affect blood pressure levels.
Doctors have traditionally focused on whether blood pressure is too high or too low. But researchers are now becoming increasingly interested in something called blood pressure variability. This refers to how much a person’s blood pressure rises and falls over time.
The new study suggests that these fluctuations themselves may be harmful to the heart.
The research was led by Ritam Patel, a medical student at Northwestern University. Patel explained that people should not only aim for “normal” blood pressure readings, but should also try to keep those readings consistent over time.
High blood pressure, also known as hypertension, is already one of the biggest risk factors for heart disease and stroke. Nearly half of adults in the United States have high blood pressure, and the risk increases with age.
Because home blood pressure monitors are now widely available, many people regularly check their blood pressure outside medical clinics. This has made it easier to track long-term patterns rather than relying on only one reading during a doctor’s appointment.
Earlier studies had already linked unstable blood pressure to several health problems, including heart disease, kidney disease, memory problems, and mental health conditions. However, this latest research specifically examined whether blood pressure swings might increase the risk of sudden cardiac death.
Sudden cardiac death happens when the heart suddenly stops working properly, often due to dangerous changes in the heart’s electrical system. It can happen without warning and is one of the leading causes of death worldwide.
For the study, researchers analyzed data from 23,499 adults. Participants were around 53 years old on average when the study began. Their blood pressure was measured at least three different times over a period of about 15 years.
The participants were then followed for up to 30 years so researchers could track cases of sudden cardiac death.
The scientists found that systolic blood pressure, which is the top number in a blood pressure reading, fluctuated by around 11 to 12 millimeters of mercury, also called mmHg, on average.
Diastolic blood pressure, the lower number, changed by about 6 to 7 mmHg on average.
Even relatively small changes appeared to matter. The researchers found that for every increase of just 1 mmHg in systolic blood pressure variability, the risk of sudden cardiac death increased by about 3%.
People whose blood pressure was the least stable had a 40% to 70% higher risk of sudden death from heart problems compared with people whose blood pressure stayed more consistent.
Dr. Donald Lloyd-Jones, a cardiovascular expert involved in the study, explained that many people think blood pressure is simply a fixed number. However, it actually changes naturally over time, and these changes may reveal hidden problems with heart health.
Although the researchers still do not fully understand why fluctuating blood pressure increases risk, one possible explanation is that constant changes may place stress on the body and blood vessels.
The heart and arteries work best under relatively stable conditions. Frequent rises and falls in blood pressure may gradually damage blood vessels, increase inflammation, or place extra strain on the heart muscle.
Some experts compare it to repeated stress on machinery. Small but constant changes over time can eventually weaken the system.
Dr. Wanpen Vongpatanasin from UT Southwestern Medical Center, who was not directly involved in the study, said more research is needed to understand what causes blood pressure to become unstable.
Possible causes could include missing blood pressure medication doses, unhealthy lifestyle habits, changes in body weight, stress, poor sleep, or other underlying health conditions.
The study itself did not test specific treatments or solutions. However, the findings suggest that maintaining a steady daily routine may help protect heart health.
Doctors recommend taking blood pressure medications exactly as prescribed, eating a healthy diet, staying physically active, managing stress, maintaining a healthy weight, limiting alcohol, and regularly checking blood pressure.
Keeping track of blood pressure over time may help doctors identify hidden risks before serious heart problems develop.
The findings also highlight the growing importance of home blood pressure monitoring. Instead of focusing only on a single reading, both patients and doctors may eventually pay closer attention to long-term patterns and stability.
Although more studies are still needed, researchers believe understanding blood pressure variability may open the door to better ways to prevent sudden cardiac death and other serious cardiovascular diseases in the future.
For now, experts say one simple message stands out clearly: protecting your heart may depend not only on lowering blood pressure, but also on keeping it as stable as possible over time.
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 health information, 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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