GBD 2023: the world got healthier per person while total health loss grew

The Global Burden of Disease Study released its 2023 estimates on 12 October, and the headline result depends entirely on which number you read. Total global disability-adjusted life-years — DALYs, the study's combined measure of years lost to early death and years lived with disability — grew 6.1 percent, from 2.64 billion in 2010 to 2.80 billion in 2023 [s1]. Over the same period, the age-standardised DALY rate, which strips out population growth and ageing, fell 12.6 percent [s1].

Both are true. A larger, older world absorbs more total health loss even as the average person's risk of losing years to disease declines. Which figure a reader takes as "the trend" determines whether the last thirteen years look like progress or deterioration.

The size of the exercise

GBD 2023 estimated burden for 375 diseases and injuries and attributable burden for 88 modifiable risk factors across 204 countries and territories, including 660 subnational locations [s1]. It drew on more than 310,000 total data sources, roughly 30 percent of them new to this estimation round, with more than 120,000 used for disease and injury burden and 59,000 for risk factors [s1]. The companion cause-of-death paper estimated mortality for 292 causes using 55,761 data sources [s2].

Uncertainty intervals throughout are the 2.5th and 97.5th percentiles of a 250-draw distribution [s1]. These are modelled estimates, not counts, and in places with weak vital registration they lean on verbal autopsy and survey data rather than death certificates [s2].

What is rising

Non-communicable diseases contributed 1.45 billion DALYs in 2010 and 1.80 billion in 2023 — while their age-standardised rate fell 4.1 percent [s1]. The leading non-communicable causes by DALY count in 2023 were ischaemic heart disease at 193 million, stroke at 157 million, and diabetes at 90.2 million [s1].

Three conditions rose on the age-standardised measure too, which is the harder test. Anxiety disorders rose 62.8 percent since 2010, depressive disorders 26.3 percent, and diabetes 14.9 percent [s1]. Those increases are not explained by more people or older people. Something about exposure, diagnosis, or both changed.

What is falling

Communicable, maternal, neonatal and nutritional diseases fell from 874 million DALYs in 2010 to 681 million in 2023, with age-standardised rates down 25.8 percent [s1]. The steepest declines were diarrhoeal diseases at 49.1 percent, HIV/AIDS at 42.9 percent, and tuberculosis at 42.2 percent [s1]. This category rose during the COVID-19 pandemic but had returned to pre-pandemic levels by 2023 [s1].

Neonatal disorders and lower respiratory infections remained the leading causes in this group, though both fell — 16.5 percent and 24.8 percent respectively [s1]. Injury-related age-standardised DALY rates fell 15.6 percent [s1].

COVID-19's exit from the rankings

The cause-of-death paper documents the pandemic's arc in the bluntest available form. COVID-19 was the leading age-standardised cause of death globally in 2021 [s2]. By 2023 it had dropped to 20th, returning the top two causes to ischaemic heart disease and stroke [s2].

The paper notes that GBD 2023 introduced a correction for misclassification of COVID-19 deaths and updated the method used to estimate them [s2]. That is a reminder that a ranking this consequential rests on modelling choices that are still being revised.

The measure that reframes everything

The cause-of-death paper introduces mean age at death as a headline metric, and it is the most legible number in either publication. Globally, the all-cause mean age at death rose from 46.8 years in 1990 to 63.4 years in 2023 [s2]. For men it went from 45.4 to 61.2; for women, from 48.5 to 65.9 [s2].

The spread around that global average is the finding. In the high-income super-region, mean age at death in 2023 reached 80.9 years for women and 74.8 for men [s2]. In sub-Saharan Africa it was 38.0 years for women and 35.6 for men [s2]. That is a gap of more than forty years in the average age at which people die, between two parts of the same world in the same year.

Some of that gap reflects age structure rather than survival alone — a population with many children and high child mortality will have a low mean age at death arithmetically. The authors distinguish observed mean age at death from an expected mean age modelled on global mortality rates and the population's own age structure, precisely so the two effects can be separated [s2].

The risk factor ledger

Nearly 50 percent of the 2.80 billion global DALYs in 2023 — 1.27 billion — were attributable to the 88 risk factors GBD analysed [s1]. The five largest contributors were high systolic blood pressure, particulate matter pollution, high fasting plasma glucose, smoking, and low birthweight and short gestation [s1]. High systolic blood pressure alone accounted for 8.4 percent of all DALYs [s1].

Attributable burden is not additive across risk factors and should not be read as a to-do list with percentages that sum. It says how much health loss is statistically associated with each exposure, under the study's assumptions about counterfactual exposure levels.

Where vaccines show up

The cause-of-death analysis reports considerable reductions in years of life lost since 1990 for vaccine-preventable diseases, most notably diphtheria, pertussis, tetanus and measles [s2]. Measles also appears among the four leading causes with the largest declines in age-standardised mortality rates across the study period, alongside diarrhoeal diseases, tuberculosis and stomach cancer [s2].

Those are 1990-to-2023 trends. They describe what immunisation programmes accomplished over three decades, not what is happening in any given month.

How to read it

GBD is the closest thing global health has to a common accounting standard, and it is a model, not a census. Its estimates for countries with sparse data carry wide uncertainty intervals that get lost when a single number is quoted. The honest summary of GBD 2023 is that per-person health outcomes continued improving through 2023, the total volume of illness kept growing because there are more and older people, and mental health and diabetes moved against the trend in a way ageing does not explain.

Sources

• Burden of 375 diseases and injuries, risk-attributable burden of 88 risk factors, and healthy life expectancy in 204 countries and territories, including 660 subnational locations, 1990–2023 — The Lancet, 12 October 2025
• Global burden of 292 causes of death in 204 countries and territories and 660 subnational locations, 1990–2023 — The Lancet, 12 October 2025