High blood pressure, also known as hypertension, is a precursor to heart disease that afflicts hundreds of millions of people worldwide but scores of this population are unaware that they have it. That was the damning conclusion of a new comprehensive study published in the Lancet. This yawning disparity is owing in large part to the absence of symptoms in the initial stages.
According to the Mayo Clinic, most people with high blood pressure have no signs or symptoms, even if blood pressure readings reach dangerously high levels.
However, as the health body notes, a few people with high blood pressure may have headaches, shortness of breath or nosebleeds.
These signs and symptoms aren’t specific and usually don’t occur until high blood pressure has reached a severe or life-threatening stage,” it warns.
What the latest research shows
Over the past 30 years, the number of adults (aged 30-79 years) living with hypertension worldwide has doubled—rising from an estimated 331 million women and 317 million men in 1990, to 626 million women and 652 million men in 2019, with most of this increase occurring in low- and middle-income countries.
The international study, published in The Lancet, analysed blood pressure measurements from more than 100 million people taken over three decades in 184 countries.
Despite being straightforward to diagnose and relatively easy to treat with low-cost drugs, nearly half of people (41 percent of women and 51 percent of men) with hypertension worldwide in 2019 were unaware of their condition; and more than half of women (53 percent) and men (62 percent) with the condition weren’t treated.
Worldwide, blood pressure was controlled (medicines were effective in bringing blood pressure to normal ranges) in fewer than one in four women and one in five men with hypertension.
Large improvements in treatment and control rates seen in some middle-income countries including Costa Rica, Kazakhstan, South Africa, Brazil, Turkey, and Iran over the past three decades show that the expansion of universal health coverage and strengthening primary care have been instrumental in improving high blood pressure care and reducing the burden of this condition.
With some of these countries, like Costa Rica, achieving treatment and control rates as good as, or better than, many high-income countries.
“Despite medical and pharmacological advances over decades, global progress in hypertension management has been slow, and the vast majority of people with hypertension remain untreated, with large disadvantages in low- and middle-income countries”, said Professor Majid Ezzati, Imperial College London, UK, the senior author of the study.
Professor Ezzati continued: “Our analysis has revealed good practice in diagnosing and treating hypertension not just in high-income countries but also in middle-income countries.
“These successes show that preventing high blood pressure and improving its detection, treatment, and control are feasible across low- and middle-income settings if international donors and national governments commit to addressing this major cause of disease and death.”
He added: “Policies that enable people in the poorest countries to access healthier foods—particularly reducing salt intake and making fruit and vegetables more affordable and accessible—alongside improving detection by expanding universal health coverage and primary care, and ensuring uninterrupted access to effective drugs, must be financed and implemented to slow the growing epidemic of high blood pressure in low- and middle-income countries.”
The Non-Communicable Disease Risk Factor Collaboration (NCD-RisC) analysed data from 1,201 population-representative studies, involving 104 million people from 184 countries (covering 99% of the world’s population).
The authors only used data from studies that had measured blood pressure to avoid biases in self-reported data.
Hypertension was defined as having systolic blood pressure of 140 mm Hg or greater, diastolic blood pressure of 90 mm Hg or greater, or taking medication for high blood pressure.
Modelling was used to estimate prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis, who were taking medication for hypertension, and whose hypertension was controlled to below 140/90 mm Hg, by country, year, and age.
What these numbers mean
Blood pressure is recorded with two numbers. The systolic pressure (higher number) is the force at which your heart pumps blood around your body.
The diastolic pressure (lower number) is the resistance to the blood flow in the blood vessels.
The authors of the study noted that whilst the study provides the first comparable estimates of blood pressure prevalence, diagnosis, treatment and control in adults for all countries of the world, it may be affected by a lack of data in some countries, especially in Oceania and sub-Saharan Africa.