Leading Causes of Death in the World

The leading cause of death in the world is the same as in the United States: heart disease. The World Health Organization counted 9.5 million deaths from ischaemic heart disease in 2023, the most recent year in its Global Health Estimates. That's about 16 percent of all deaths on earth, which makes it the single biggest killer of people worldwide.^[1]

This page covers the global number one, the full top ten, how the world's list differs from the American one, and why a rich country and a poor country don’t die of the same things. The WHO's most recent complete estimates are for 2023, the year COVID-19 dropped out of the global top ten. Every figure carries its year and links to its source.

Ischaemic heart disease, the coronary artery disease that also leads in the United States. The WHO counted 9.5 million deaths from it in 2023, about 16 percent of all deaths worldwide, and it was the leading cause in 2000 too. Deaths from it rose by 3.0 million between 2000 and 2023.^[1]

Total deaths worldwide in 2023 were 61 million. The ten leading causes together accounted for 33 million of them, or 54 percent. Eight of those ten are noncommunicable diseases, the chronic conditions of aging populations rather than infections.^[1]

Here are the ten leading causes of death worldwide in 2023, ranked, from the WHO's Global Health Estimates, with the estimated number of deaths:^[1][2]

1. Ischaemic heart disease: 9.5 million
2. Stroke: 6.8 million
3. Chronic obstructive pulmonary disease (COPD): 3.6 million
4. Lower respiratory infections: 2.7 million
5. Alzheimer disease and other dementias: 2.1 million
6. Diabetes mellitus: 2.0 million
7. Trachea, bronchus and lung cancers: 1.8 million
8. Hypertensive heart disease: 1.6 million
9. Kidney diseases: 1.4 million
10. Diarrhoeal diseases: 1.2 million

Two of the lower ranks are worth naming. Diabetes ranked sixth, and its deaths are more than double the 2000 count. Kidney disease climbed from the world's seventeenth leading cause of death to the ninth, with deaths up 86 percent between 2000 and 2023.^[1] The eighth cause, hypertensive heart disease, is the damage chronic high blood pressure does to the heart itself.

Counted separately from the ischaemic heart disease at the top of the list, it means two of the world's ten deadliest conditions are forms of heart disease.

In 2023, COVID-19 ranked fourteenth, with 0.9 million deaths directly attributed to it, and it dropped out of the global top ten for the first time since the pandemic began in 2020.^[1]

At the pandemic's peak the numbers were far higher. The WHO's current estimates put COVID-19 deaths at 5.3 million in 2020, when it ranked third, and 9.4 million in 2021, when it was the leading cause of death worldwide. These figures replace the WHO's earlier 2021 estimate, because the 2000 to 2023 estimates use updated data and methods and aren't comparable with earlier releases.^[1][2]

The very top of both lists is the same: heart disease is number one in the world and number one in the United States. Below that, the two lists diverge. The American list is almost entirely chronic, noncommunicable disease: heart disease, cancer, accidents, stroke, and chronic lung disease fill the top five. The global list still carries infections high up, with lower respiratory infections at number four and diarrhoeal diseases at number ten in 2023.^[1][2][3]

Cancer is where the ranking looks most different, and the difference is mostly bookkeeping. In the US, all cancers are counted together as one cause, which puts cancer second nationally, with 619,876 deaths in 2024.^[3] The WHO splits cancer by the part of the body it starts in, so lung cancer alone ranks seventh worldwide at 1.8 million, and the other cancers sit lower on their own lines.^[1] Counted the same way, cancer is a leading cause in both places.

This is where the global picture splits hardest. In low-income countries, seven of the top ten causes of death in 2023 were communicable diseases, the infections that wealthy countries mostly stopped dying from decades ago. Malaria, tuberculosis, and HIV and AIDS all remained in the low-income top ten. Lower respiratory infections have been the leading cause of death in low-income countries since around 2010, except in 2021, and diarrhoeal diseases ranked fifth in 2023.^[1]

In high-income countries, nine of the ten leading causes of death in 2023 were noncommunicable diseases, and deaths from most of the leading causes are rising as populations age. Ischaemic heart disease and stroke stayed in the top three from 2000 to 2023, dementia became the third leading cause in 2023, and lower respiratory infections, ranked sixth, were the only other communicable disease on the list.^[1]

The same disease that leads both lists, heart disease, is reached by very different routes: in higher-income countries alongside older population structures, and in lower-income countries alongside infectious diseases and other conditions affected by access to prevention, diagnosis, and treatment.

Heart disease ranks first worldwide, was first in upper-middle-income countries in 2023, and was in the top three in lower-middle-income and high-income countries.^[1] The things that cause it are nearly everywhere: high blood pressure, tobacco, poor diet, and inactivity, plus the plain fact of getting older.

As countries grow wealthier and people live longer, infections kill fewer of them, and more people survive to the age when coronary artery disease becomes fatal. Heart disease rises to the top as a country develops.

Much of that toll is preventable. The WHO reports that ischaemic heart disease deaths rose by 3.0 million between 2000 and 2023.^[1] The main risk factors respond to blood pressure control, tobacco reduction, and diet. That's why it's both the world's biggest killer and one of the causes public health spends the most effort trying to move.

The WHO's Global Health Estimates pull together death registration data, surveys, and statistical models from countries around the world, then apply one consistent set of coding rules so the numbers can be compared across borders. Causes are defined by International Classification of Diseases codes, the same classification national statistics offices use for registered deaths.^[2]

The most recent complete year in the estimates is 2023, which the WHO released in 2026. Global figures lag further behind than any single country's, because the WHO has to wait for data from many countries and fill gaps where registration is incomplete. That's why the current worldwide ranking is for 2023, while the United States already has final 2024 data of its own.^[1][3]

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This page is death education. It doesn’t replace medical advice. Figures are the World Health Organization's Global Health Estimates for 2023 and the CDC's 2024 final US data; see our Sources and Methodology. For how the same causes rank inside the United States, and by age, see Leading Causes of Death in America and Leading Causes of Death by Age.