Related: our coverage of what the WHO says about climate change and health.
The World Health Organization released its latest global mortality estimates on 2 October 2026, covering trends from 2000 to 2023 across more than 160 diseases and injuries. The headline is a shift in what kills people, and it differs sharply depending on where you live.
Two findings dominate. First, noncommunicable diseases now account for 8 of the 10 leading causes of death. Second, the causes that kill people in a low-income country are almost entirely different from those that kill people in a high-income one — which makes “the leading causes of death” a phrase that needs qualifying.
The headline figures
In 2023, the 10 leading causes of death accounted for 33 million deaths, or 54% of the total 61 million deaths worldwide.
| Rank | Cause | Deaths in 2023 | Share of global deaths |
|---|---|---|---|
| 1 | Ischaemic heart disease | 9.5 million | 16% |
| 2 | Stroke | 6.8 million | 11% |
| 3 | Chronic obstructive pulmonary disease | 3.6 million | 6% |
| 4 | Lower respiratory infections | 2.7 million | — |
| 5 | Alzheimer’s disease and other dementias | 2.1 million | — |
| 6 | Diabetes | 2.0 million | — |
| 7 | Trachea, bronchus and lung cancers | 1.8 million | — |
| 9 | Kidney diseases | — | — |
Two of these deserve emphasis. Ischaemic heart disease has seen the largest increase in deaths of any cause since 2000, rising by 3.0 million to 9.5 million. Kidney diseases climbed from the seventeenth leading cause to the ninth, with deaths up 86% between 2000 and 2023.
COVID-19 has left the top 10
The most newsworthy change is an absence. COVID-19 dropped out of the 10 leading causes of death globally for the first time since the pandemic began.
The trajectory over four years is stark:
- 2020: third leading cause of death, an estimated 5.3 million deaths
- 2021: first leading cause of death, 9.4 million deaths
- 2022 and 2023: declining trend
- 2023: 0.9 million deaths directly attributable, the fourteenth leading cause — down 85% from its 2021 peak in upper-middle-income countries
Lower respiratory infections reclaimed fourth place as the world’s deadliest communicable disease in 2023. The WHO attributes this partly to COVID-19 no longer competing as the dominant respiratory cause, with deaths returning to the pre-pandemic 2019 level.
Two public health successes in the same data
The reverse direction is equally striking. Two diseases were in the top 10 in 2000 and are no longer there:
- HIV and AIDS — deaths fell by 62%, moving from the seventh leading cause of death in 2000 to the twenty-second in 2023.
- Preterm birth complications — deaths fell by 30%, from eighth place to sixteenth.
These are among the most significant mortality gains of the period, and they sit in the same dataset as the rising kidney disease numbers. Progress and reversal, recorded in the same table.
The causes of death are completely different by income
This is the most important section for anyone trying to apply these figures to a specific country. The WHO groups economies into four income categories, and the composition of the top 10 changes almost entirely between them.
Low-income countries
People are far more likely to die of a communicable disease. Seven of the top 10 causes here are communicable diseases. Malaria, tuberculosis and HIV/AIDS all remain in the top 10, though all fell significantly — HIV/AIDS deaths are down 62% since 2000.
Diarrhoeal diseases ranked fifth in 2023, down from first place in 2000, with fatalities roughly halving. Notably, COPD does not appear in the top 10 here, while it does in every other income group.
Lower respiratory infections have led this category since around 2010 — except in 2021, when COVID-19 overtook them. Progress here has stalled: annual deaths exceeded 350,000 throughout 2000–2023 with no notable downward trend.
Lower-middle-income countries
A balanced picture: five noncommunicable diseases, four communicable/maternal/neonatal/nutritional conditions, and one injury (road injury).
Deaths from ischaemic heart disease, stroke and COPD all roughly doubled between 2000 and 2023, moving from fourth, fifth and seventh respectively to the top three. Diabetes moved from fifteenth to fifth, with deaths more than tripling.
Upper-middle-income countries
Eight of the top 10 causes are noncommunicable diseases. The only two communicable entries are lower respiratory infections (sixth) and COVID-19 (tenth) — this is the only income group where COVID-19 still ranked in the top 10 in 2023.
Lung cancer deaths have more than doubled here, with 520,000 extra deaths — more than three times the increase of all three other income groups combined. Ischaemic heart disease deaths rose by nearly 1.8 million, the largest absolute increase in any group.
High-income countries
Nine of the top 10 causes are noncommunicable diseases, with rising deaths across most of them — primarily due to population ageing.
Three exceptions went the other way: ischaemic heart disease down 18%, stroke down 26%, and stomach cancer down 27%. This is the only income group where deaths from these three fell.
Alzheimer’s disease and other dementias nearly quadrupled since 2000, becoming the third leading cause of death in high-income countries in 2023, up from seventh. This overtook lung cancer, which fell from third to fourth.
Why the WHO publishes this
The WHO’s stated rationale is worth quoting in substance, because it explains why this data shapes policy rather than merely describing it.
Understanding why people die is essential to improving how people live. Mortality data lets policymakers identify health risks, recognise preventable causes, evaluate what works, and direct resources where they are needed most. It also reaches beyond the health sector — into transport, food and agriculture, and environmental protection.
The WHO develops standards through the International Classification of Diseases (ICD-11), a digital platform countries use to generate comparable health data.
The caveat the WHO puts first
Before the figures, the honest limitation:
Collecting accurate and comprehensive mortality data remains a major challenge, particularly in many low-income countries. Data collection systems are often fragmented, incomplete or inconsistent, meaning policy-makers may still lack reliable information on how many people die, when, and from what.
This matters for reading the whole table. The cleanest data comes from the countries with the best-resourced death registration. Where deaths are under-registered, the burden is likely understated — and the countries most affected by that gap are those whose disease burden is heaviest.
Frequently asked questions
What is the world’s biggest killer?
Ischaemic heart disease, responsible for 16% of the world’s total deaths — 9.5 million in 2023. It also recorded the largest increase in deaths since 2000, rising by 3.0 million.
Is COVID-19 still a leading cause of death?
No. COVID-19 dropped out of the 10 leading causes of death globally in 2023 for the first time since the pandemic began, falling to 0.9 million deaths directly attributable and the fourteenth leading cause. It was the first leading cause in 2021.
How many people died in 2023?
There were 61 million deaths worldwide in 2023. The top 10 causes accounted for 33 million of them, or 54%.
Which diseases have improved most since 2000?
HIV/AIDS, with deaths down 62%, falling from the seventh leading cause to the twenty-second. Preterm birth complications fell 30%, from eighth to sixteenth. Diarrhoeal deaths in low-income countries roughly halved.
Which diseases are rising fastest?
Kidney diseases, up 86% between 2000 and 2023 and rising from the seventeenth leading cause to the ninth. Diabetes in lower-middle-income countries, where deaths more than tripled and the cause moved from fifteenth to fifth place.
Do these numbers apply to India?
They apply at a global or income-group level. The WHO does not publish a cause-of-death breakdown for every individual country in this fact sheet, and country patterns differ substantially within each income group. For India-specific figures, use the national registration data rather than these global estimates.
Sources
- World Health Organization, “The top 10 causes of death” fact sheet, 2 October 2026: who.int
- WHO Global Health Estimates 2026, reporting trends for more than 160 diseases and injuries from 2000 to 2023, as cited in the fact sheet.
- World Health Organization, International Classification of Diseases (ICD-11): who.int
- World Health Organization, “New WHO estimates show changing global health landscape,” 2 October 2026.
- The World Bank, Country and Lending Groups (income classification referenced by WHO): datahelpdesk.worldbank.org
This article summarises published WHO mortality estimates. The WHO states that mortality data collection remains a major challenge, particularly in low-income countries, so figures should be read as the best available global estimates rather than precise counts. This is general information and not a statement about any individual’s risk.
