For most of human history, the things most likely to kill you were things you caught.
Pneumonia, tuberculosis, diarrheal disease, and other infections dominated the causes of death. Over the last century, that reality quietly flipped.
Today the biggest threats to human health are largely chronic conditions that build over years, not germs that strike in days.
Public health researchers call this shift the epidemiological transition, and it has reshaped what it means to stay well.
TL;DR
- Noncommunicable diseases, such as heart disease, cancer, chronic respiratory illness, and diabetes, now cause roughly 74% of all deaths worldwide, about 41 million a year.
- This marks a historic shift from infectious disease to chronic disease as the leading threat to health.
- The burden falls hardest on low- and middle-income countries, where most premature noncommunicable disease deaths occur.
Data anchored to the World Health Organization noncommunicable diseases fact sheet.
| wdt_ID | wdt_created_by | wdt_created_at | wdt_last_edited_by | wdt_last_edited_at | Cause category | Share of global deaths | Approximate annual deaths |
|---|---|---|---|---|---|---|---|
| 1 | emmanuel-ashemiriogwa | 21/08/2026 10:16 AM | emmanuel-ashemiriogwa | 21/08/2026 10:16 AM | Noncommunicable diseases (total) | About 74% | About 41 million |
| 2 | emmanuel-ashemiriogwa | 21/08/2026 10:16 AM | emmanuel-ashemiriogwa | 21/08/2026 10:16 AM | Cardiovascular diseases | Largest single group | At least 19 million |
| 3 | emmanuel-ashemiriogwa | 21/08/2026 10:16 AM | emmanuel-ashemiriogwa | 21/08/2026 10:16 AM | Cancers | Second largest | About 10 million |
| 4 | emmanuel-ashemiriogwa | 21/08/2026 10:16 AM | emmanuel-ashemiriogwa | 21/08/2026 10:16 AM | Chronic respiratory diseases | Third | About 4 million |
| 5 | emmanuel-ashemiriogwa | 21/08/2026 10:16 AM | emmanuel-ashemiriogwa | 21/08/2026 10:16 AM | Diabetes (including related kidney disease) | Fourth | Over 2 million |
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The great flip
A century ago, the leading causes of death were infectious.
As sanitation, vaccines, antibiotics, and nutrition improved, fewer people died young from infection, and more lived long enough to develop the slow diseases of later life.
The scoreboard tells the story: today, 7 of the 10 leading causes of death globally are noncommunicable diseases.
Cardiovascular disease alone accounts for at least 19 million deaths a year, followed by cancers at around 10 million.
Not just a rich-world problem
There is a common assumption that chronic disease is a wealthy-country problem, a consequence of abundance.
The data says otherwise.
The transition is now global, and its sharpest edge falls on lower-income countries.
Of the roughly 17 to 18 million people who die prematurely, before age 70, from noncommunicable diseases each year, the large majority of those premature deaths occur in low- and middle-income nations.
Many of these deaths are considered preventable, which is what makes the pattern an issue of fairness as much as biology.
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ELI5
Long ago, most people died from diseases they caught, like infections.
Now that we have vaccines and clean water, most people live long enough to get slow diseases instead, like heart disease and cancer.
These now cause about three-quarters of all deaths in the world.
Sources
