More than half of people with this serious heart health risk don’t even know they have it, according to a new study.

When something is wrong, we often look to our body to give us clues. A sore throat, persistent pain, or unusual rash may indicate that it may be time to make a doctor’s appointment. But some health problems can develop without visible symptoms, making them harder to detect. One example is high blood pressure, also known as hypertension.

Hypertension affects nearly half of American adults, but many people with high blood pressure don’t know they have it or don’t control it. Because it often develops without symptoms, it can be difficult to determine when to see a doctor. This is concerning because high blood pressure is a major risk factor for heart disease and death worldwide.

Recently, a study published in Public Health BMJ looked at how common hypertension is among adults in England and how often the disease goes undetected or goes uncontrolled. Their findings highlight how this often silent disease can go unnoticed and why screening and early detection are so important.

How was the study conducted?

To assess the prevalence, detection, treatment and control of hypertension, researchers analyzed data from the Our Future Health study, a large-scale research program that collects information on the health of adults in the UK. For this specific analysis, they focused on more than 1.4 million adults ages 18 and older who had blood pressure measurements.

At enrollment, participants’ blood pressure was measured using an automated device. Researchers defined hypertension according to World Health Organization guidelines as systolic blood pressure (SBP) ≥140 mm Hg, diastolic blood pressure (DBP) ≥90 mm Hg, or self-reported use of hypotensive medications. They also explained whether participants’ hypertension was detected, whether they received treatment, and whether their blood pressure was controlled. Controlled hypertension was defined as SBP <140 mm Hg and DBP <90 mm Hg.

Using these data, researchers examined how the prevalence, detection, and control of hypertension varied among participants.

What did the study reveal?

Despite the health risks associated with high blood pressure, many people in the study had high blood pressure without knowing it. In fact, researchers found that about 37.2% of participants had high blood pressure, and 58.8% of those who had high blood pressure did not know they had high blood pressure. This means they did not self-report a previous diagnosis or report taking hypotensive medications.

Additionally, the researchers found that among participants who did not report a diagnosis of hypertension, 33.2% of men and 21.2% of women had blood pressure ≥140/90 mm Hg. Although this suggests that undetected hypertension was common among both men and women, the percentage was higher among men. Researchers also found that higher body mass index, smoking, alcohol consumption, and a personal or family history of heart disease were associated with a higher risk of hypertension.

Interestingly, the findings also highlighted the challenges of managing and treating high blood pressure. Among participants taking blood pressure medications, 50.2% still had blood pressure ≥140/90 mm Hg, meaning their hypertension was not controlled according to study parameters.

Together, these findings reflect the commonly described “rule of halves,” which suggests that about half of people with hypertension are unaware of their condition and about half of those who receive treatment fail to control their blood pressure.

It is important to note that this study had some limitations. The data used in this study measured participants’ blood pressure at the time of enrollment, which provides a snapshot of their blood pressure at that time rather than following repeated measurements over time. Because blood pressure can fluctuate, a single high reading does not necessarily confirm a diagnosis of hypertension. This means that some participants may have needed additional blood pressure measurements to confirm their diagnosis.

How does this apply to real life?

Despite the prevalence of high blood pressure, the results of this study suggest that many people living with the condition may be unaware of it. This is concerning because high blood pressure increases the risk of several health problems, including heart disease, heart attacks, and strokes. It can also contribute to chronic kidney failure, vision loss and dementia.

High blood pressure often has no visible warning signs or symptoms, so many people do not know they have it. Checking your blood pressure regularly is one of the most important steps you can take to quickly identify high blood pressure. In addition to routine checkups, certain heart-healthy lifestyle habits can help prevent or manage hypertension.

• Practice regular physical activity. Consistent physical activity can help lower blood pressure and support overall heart health. Many experts recommend aiming for around 150 minutes of moderate-intensity activity each week.
• Eat a balanced diet. A diet rich in fruits, vegetables and whole grains can help prevent or manage high blood pressure. Limiting sodium and alcohol can also help.
• Manage health conditions that may put you at higher risk. Conditions such as diabetes and obesity can increase your risk of developing high blood pressure. Additionally, high blood pressure can occur during pregnancy, making prenatal care important.
• Take care of your mental health. Chronic stress and certain mental health problems may be associated with higher blood pressure. Finding healthy ways to manage stress and seeking support when needed can benefit your overall health.
• Stop smoking. Smoking can raise your blood pressure and increase your risk of heart disease and stroke. Quitting smoking can improve your heart health.
• Know your medical history. Understanding your personal medical history as well as family history of high blood pressure can help you and your healthcare provider assess your risk.
• Stay on top preventive care. Have your blood pressure checked during routine doctor visits.

Our expert opinion

A new study published in Public Health BMJ found that more than a third of participants had hypertension, but more than half of people with the condition had undetected high blood pressure. These findings highlight the importance of improving blood pressure awareness and screening at the population level. Staying current on preventative care, knowing your personal and family health history, and adopting heart-healthy lifestyle habits can help you manage your blood pressure and maintain your overall health.