In theory, hypertension is a disease that is both easy to test for and readily treatable with existing medications and lifestyle interventions.
However, a new global analysis by Tulane University found that high blood pressure remains a stubborn and deadly silent epidemic whose burden on public health systems has only increased in the past 20 years, particularly in countries least equipped to address it.
The study, published in the Journal of the American College of Cardiology , found that the prevalence of hypertension has decreased slightly in high-income countries from 2000 to 2020, but has substantially increased in low- to middle-income countries. Nearly 90% of the increase in adults with hypertension occurred in low- and middle-income countries.
Hypertension, the world's leading preventable cause of premature death, now affects 33% of the world's adults — about 1.7 billion people — as of 2020. The disease claims an estimated 10 million lives annually. "This study shows that there is urgent work to be done everywhere," said lead author Samantha O'Connell, doctoral researcher in the Celia Scott Weatherhead School of Public Health and Tropical Medicine at Tulane University. "What surprised me was that awareness, treatment and control are not where they need to be, not only in low- and middle-income countries but also in high-income countries."
Hypertension is a major contributor to heart attacks, strokes, kidney disease and dementia, yet it often has no symptoms, leading to gaps in diagnoses. Even after diagnosis, controlling hypertension can be difficult. Physicians may not always follow the latest treatment guidelines, and patients may struggle to take medication consistently or make long-term lifestyle changes.
In 2020, less than 20% of adults with hypertension worldwide had their blood pressure controlled. Control rates were nearly three times greater in high-income countries than in low- and middle-income countries — 40.2% in high-income countries compared with 13.6% in low- and middle-income countries.
"While we have made some progress in hypertension control, it is still extremely low globally," said senior author Katherine Mills, professor of epidemiology at the Celia Scott Weatherhead School of Public Health and Tropical Medicine at Tulane University. "This is not just a story about low- and middle-income countries. Control is still only about 40% in high-income countries, despite the fact that we have effective interventions to control hypertension."
The study is one of the most comprehensive analyses of global hypertension trends to date, pooling data from 287 population-based studies involving more than six million adults across 119 countries. Researchers examined changes in hypertension prevalence, awareness, treatment and control.
Latin America, the Caribbean and sub-Saharan Africa had the highest hypertension prevalence as of 2020. The largest total number of adults with hypertension was in East Asia and the Pacific, followed by South Asia.
Researchers also found that the disparity in hypertension prevalence has grown over time. In 2000, 70% of adults with uncontrolled hypertension lived in low- and middle-income countries. By 2020, that share had risen to 83%.
A high prevalence of hypertension can impose huge financial burdens on any healthcare system. But researchers noted that low- and middle-income countries' health systems also must manage and prioritize a heavy burden of infectious diseases and maternal and child health needs, while facing limited resources for chronic disease care.
The findings underscore the need to better implement proven strategies, including wider access to affordable blood pressure medications, team-based care, accurate blood pressure measurement, simpler treatment protocols and health systems designed to support long-term management of chronic diseases.
"There are barriers to hypertension control at the patient level, like medication adherence and making lifestyle changes, but there are also many barriers at the clinician level and at the system level," Mills said. "That is why it is so challenging to control. We have to address all of them in order to meaningfully improve these numbers."
