Which two things cause a quarter of all deaths in the world?

Of all the people who died in 2012 (approximately 56 million in total), more than half died from just 10 causes.

Even more remarkable, just two leading causes of death — stroke and ischemic heart disease — were together responsible for a full quarter of those deaths.

Here’s a look at the data, from the World Health Organization:

World Health Organization

A stroke occurs when a blood clot blocks a blood vessel, cutting off blood flow to the brain. The resulting death of brain cells can cause severe disability and death.

Ischemic heart disease, also called coronary artery disease, involves the hardening and narrowing of the arteries. Oxygen can’t reach the heart as effectively, which can weaken the muscle over time and end in heart failure. Ischemic heart disease also frequently leads to a heart attack, which is when a blood clot blocks the flow of blood to the heart.

The biggest risk factors for cardiovascular diseases are smoking, inactivity, and an unhealthy diet.

A global problem

Around the world, noncommunicable diseases — the biggest of which are cardiovascular diseases, cancers, diabetes, and chronic lung diseases — caused 68% of all deaths in 2012. Such diseases are often seen as the scourge of rich countries, but that’s not entirely true.

Noncommunicable diseases caused 87% of deaths in high-income countries (like the US) in 2012 and just 37% of deaths in low-income countries (like Afghanistan). They are also leading causes of death in lower-middle-income countries like Vietnam (57% of all deaths) and upper-middle-income countries like Brazil (81% of all deaths).

Rates of death from cardiovascular diseases in particular are increasing rapidly in developing countries.

Complicating the picture even further, the people at the highest risk of dying from cardiovascular diseases in rich countries are low-income residents.

Curbing the number of people who die from ischemic heart disease and stroke around the world would save millions of lives. And the key tool in this fight will be focusing on prevention, not potential cures. There’s no real secret to saving these lives, which makes the task at hand both easier and harder than other public health challenges around the world.

“Unless current trends are halted or reversed, over a billion people will die from cardiovascular disease in the first half of the 21st century,” Anthony Rodgers, a researcher at the University of Auckland, New Zealand, said in a World Health Organization report. “This would be an enormous tragedy, given that research in the last half of the 20th century showed that cardiovascular disease was largely preventable.”

This article is published in collaboration with Business Insider. Publication does not imply endorsement of views by the World Economic Forum.

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Author: Lauren F. Friedman writes and edits science stories at Business Insider and oversees the site’s health coverage. 

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