Over 1 billion people have hypertension - but half of them don’t even know it. What exactly is this ‘silent killer’?

As many as 1.2 billion people could be living with hypertension and half of them don’t even realize they have this potentially life-threatening condition.

Also known as high blood pressure, hypertension can bring on a range of very serious illnesses and ailments, including organ failure, blindness, heart attacks and strokes. The US Centers for Disease Control and Prevention refer to high blood pressure as “the ‘silent killer’ because it usually has no warning signs or symptoms, and many people do not know they have it”.

In a joint study with Imperial College London, the World Health Organization (WHO) has looked at data from over 100 million people aged 30-79 years in 184 countries, during the period 1990-2019, to assess the global state of blood pressure measurement and treatment.

Since 1990, the number of people living with hypertension has leapt from 650 million to 1.28 billion, according to the report. That is more down to increasing life expectancy and population growth, rather than a rise in the prevalence of high blood pressure per head of population, WHO says.

However, there is a greater incidence of hypertension in low- and middle-income countries, which are home to around 82% of people with the condition. What’s more, people in sub-Saharan Africa, central, south and south-east Asia, and Pacific Island nations are among the least likely to receive medication, says the WHO.

“We have the tools to prevent, diagnose and manage hypertension. Our challenge is to make sure everyone with hypertension has access to those tools,” said WHO Director-General, Dr Tedros Adhanom Ghebreyesus, speaking at the launch of a new set of guidelines for the pharmacological treatment of hypertension in adults.

One of the report’s conclusions was that around 580 million people living with hypertension have not had their condition diagnosed. Furthermore, 720 million people are not getting the treatment they need for their high blood pressure.

“Nearly half a century after we started treating hypertension, which is easy to diagnose and treat with low-cost medicines, it is a public health failure that so many of the people with high blood pressure in the world are still not getting the treatment they need,” said Majid Ezzati, Professor of Global Environmental Health at Imperial College London.

Medication for hypertension is relatively cheap and readily available, but it is not the only course of action for treating the condition. “​​Pharmacological treatment should always be combined with healthier diets and regular physical activity; more strictly controlling tobacco products; and identifying and treating comorbidities such as diabetes and pre-existing heart disease,” Dr Ghebreyesus said.