Causes of Death — Long-Run Shift
In 1900, infectious diseases — tuberculosis, pneumonia, diarrhoea, measles — caused more than half of all deaths worldwide. In 2024, non-communicable diseases (cardiovascular, cancer, respiratory, diabetes) cause 74% of deaths. This 'epidemiologic transition' is one of the largest structural changes in human mortality since records began.
Key insights
Infectious disease has not disappeared
Globally infectious diseases still cause around 8 million deaths a year — lower respiratory infections, TB, HIV, diarrhoeal disease, and malaria lead the list. In sub-Saharan Africa infectious disease remains the largest category. The shift to NCD-dominance is most complete in high-income countries; the rest of the world is at varying points along the same curve.
Cardiovascular disease has been #1 for half a century
Ischaemic heart disease and stroke together kill 17.9 million people a year — more than 30% of all deaths. The age-standardised rate has fallen substantially since 1990 in high-income countries (reduced smoking, statins, hypertension treatment, surgical advances) but absolute numbers continue to rise as populations age.
Dementia is the fastest-rising cause
Deaths attributed to Alzheimer's and other dementias have more than doubled since 2000 to 1.8 million globally. Most of the rise reflects improved diagnosis and longer life expectancy — people are surviving cardiovascular events long enough to develop dementia. It is now the seventh-leading cause of death worldwide.
Top causes of death — global 2024
Annual deaths, millions
Key Finding: Cardiovascular disease (heart attacks + stroke) accounts for nearly one in three deaths.
Causes of death by category — long-run shift
% of global deaths, by major category
Key Finding: Infectious disease share fell from >50% (1900) to 13% (2024); NCD share rose from <30% to 74%.
Methodology & caveats
Defining categories
WHO's Global Health Estimates split deaths into three top-level groups: Group 1 (communicable, maternal, perinatal, nutritional), Group 2 (non-communicable diseases), and Group 3 (injuries). Categories nest down to hundreds of specific causes. Different studies use slightly different boundaries — always check the grouping.
Cause attribution
A death often has multiple causes (a heart attack in a person with diabetes and obesity). National statistics offices use the WHO International Classification of Diseases to pick a single underlying cause. Multiple-cause analysis tells a richer story but is harder to compare across countries.
Historical reconstruction
Pre-1950 cause-of-death data is reconstructed from civil registration in Western Europe and the US, hospital records elsewhere, and modelled estimates for the rest. Confidence intervals widen rapidly going back further. The broad pattern of epidemiologic transition is robust; specific numbers in the 1900–1950 range carry substantial uncertainty.