Global Stroke Burden Keeps Rising Despite Prevention Efforts

The Stroke That Wouldn’t Quit

In 2021, stroke killed 7.3 million people. That is more than the populations of New York City, London, and Tokyo combined. It was the third leading cause of death worldwide, behind only heart disease and COVID-19. But here is the part that should keep neurologists up at night: after decades of public health campaigns, blood pressure screenings, and warnings about salt and smoking, the global burden of stroke is not shrinking. It is growing.

Valery L. Feigin and a team of over 100 coauthors from the Global Burden of Disease Study published a sobering update in The Lancet Neurology this year (Feigin et al., 2024). They analyzed 31 years of data across 204 countries, tracking every stroke from 1990 to 2021. What they found is not a story of progress. It is a story of a disease that has learned to adapt faster than our prevention efforts can catch up.

The Numbers That Refuse to Budge

Let me give you the headline numbers, because they matter.

In 2021, there were 93.8 million people living with stroke worldwide. That is nearly one in every 85 humans. There were 11.9 million new strokes that year alone (Feigin et al., 2024). But the real shock is the trend line. From 1990 to 2021, the absolute number of strokes, deaths, and disability-adjusted life years (DALYs) all increased. The age standardized rates did decline slightly, which is the good news masked by an aging population. But here is the bad news: that decline stopped around 2015.

Feigin and colleagues found a "stagnation in the reduction of incidence from 2015 onwards" (Feigin et al., 2024). In some regions, rates actually started climbing again. Southeast Asia, East Asia, and Oceania saw increases in stroke incidence, death, and prevalence. So did countries with lower socioeconomic development. And so did people under 70 years old.

Stroke is no longer just a disease of the old. It is increasingly striking people in their 50s, 40s, and even younger.

How They Counted Every Stroke

This study is not a small survey. It is a systematic analysis using the standard methodology of the Global Burden of Disease Study, which is the most comprehensive epidemiological effort ever undertaken. The team estimated incidence, prevalence, death, and DALY counts for three types of stroke: ischemic stroke (caused by clots), intracerebral hemorrhage (bleeding inside the brain), and subarachnoid hemorrhage (bleeding around the brain). They broke the data down by 204 countries, 21 regions, and five levels of the Socio-demographic Index, which combines income, education, and fertility.

To calculate the burden attributable to risk factors, they used a method called comparative risk assessment. They estimated the fraction of stroke that would have been prevented if exposure to a given risk factor had been reduced to a theoretical minimum level. They then propagated uncertainty through 500 statistical draws to generate 95% uncertainty intervals for every estimate (Feigin et al., 2024).

This is not guesswork. It is the closest thing we have to a global census of stroke.

The Typology of a Stroke

Not all strokes are created equal. Globally, ischemic strokes made up 65.3% of incident strokes in 2021. Intracerebral hemorrhage accounted for 28.8%, and subarachnoid hemorrhage for 5.8% (Feigin et al., 2024). These proportions matter because the risk factors differ. High blood pressure is the dominant driver of hemorrhagic stroke. Clotting factors, atrial fibrillation, and cholesterol play bigger roles in ischemic stroke.

But the authors found that the metabolic risk factors high blood pressure, high body mass index, and high fasting plasma glucose are now the three biggest contributors to stroke DALYs worldwide. And all three are rising.

The Risk Factors That Are Winning

This is where the paper delivers its most uncomfortable finding. The authors calculated the change in stroke DALYs attributable to 23 risk factors from 1990 to 2021. Some risk factors declined. Smoking, for example, dropped in many high income countries. But several risk factors surged.

Here are the increases in DALYs attributable to specific risk factors, as reported by Feigin et al. (2024):

• ▸High body mass index: up 88.2%
• ▸High ambient temperature: up 72.4%
• ▸High fasting plasma glucose: up 32.1%
• ▸Diet high in sugar sweetened beverages: up 23.4%
• ▸Low physical activity: up 11.3%
• ▸High systolic blood pressure: up 6.7%
• ▸Lead exposure: up 6.5%
• ▸Diet low in omega 6 polyunsaturated fatty acids: up 5.3%

Let me translate that. The biggest driver of the rising stroke burden is not something exotic. It is obesity. High BMI alone accounted for an 88% increase in stroke related disability. That is not a typo. Eighty eight percent.

The second biggest is climate change. High ambient temperature increased stroke burden by 72%. This is consistent with emerging research showing that extreme heat stresses the cardiovascular system, increases blood viscosity, and triggers more clotting events. Stroke is now a climate sensitive disease.

Then there is the metabolic cluster: diabetes, high blood pressure, and poor diet. These are the classic risk factors, but they are getting worse, not better. The authors found that high fasting plasma glucose increased stroke burden by 32%, and diets high in sugar sweetened beverages increased it by 23%.

The Geography of Stroke

Stroke burden is not evenly distributed. The authors found stark disparities by region and by socioeconomic development.

Countries in the low and low middle SDI quintiles bore the heaviest burden. They had the highest age standardized rates of stroke death and DALYs. And unlike high income countries, where rates have been slowly declining, these regions saw increases or stagnation.

Southeast Asia, East Asia, and Oceania were the worst hit. The authors found "increases in the stroke incidence, death, prevalence, and DALY rates" in these regions (Feigin et al., 2024). This is partly due to aging populations, but also due to rising rates of hypertension, obesity, and air pollution.

Air pollution deserves special mention. It is a major risk factor for stroke, particularly in low and middle income countries. The authors found that air pollution (ambient particulate matter and household air pollution) remained a top contributor to stroke burden in these regions.

What This Does Not Prove

This study is correlational, not experimental. It shows associations between risk factors and stroke burden, but it cannot prove causation in the strict sense. The comparative risk assessment method assumes that the relationship between a risk factor and stroke is causal, which is supported by decades of randomized trials and cohort studies. But the magnitude of the effect depends on the quality of the exposure data, which varies by country.

Also, the study does not account for all possible risk factors. Genetic predisposition, sleep disorders, and certain infections are not included. The authors note that their estimates for some risk factors, like diet and physical activity, rely on self reported data, which is notoriously unreliable.

Finally, the study cannot tell us why the decline in stroke rates stalled after 2015. It could be due to changes in risk factor trends, improvements in acute care that kept more people alive but disabled, or shifts in diagnostic practices. The authors themselves call for better stroke surveillance to answer this question.

What Actually Changed

This study updates the previous Global Burden of Disease estimates from 2019. The new data show that stroke has moved from the fourth leading cause of DALYs to the third, behind ischemic heart disease and COVID-19. That is a shift in the global disease hierarchy.

But the bigger story is the stagnation. For decades, public health officials assumed that stroke prevention was a solved problem. Control blood pressure, stop smoking, eat better, exercise more. The data from high income countries supported this optimism. But the global picture tells a different story. The gains are real but fragile, and they are being eroded by rising obesity, aging populations, and climate change.

The authors write that "effective, accessible, and affordable measures to improve stroke surveillance, prevention (with the emphasis on blood pressure, lifestyle, and environmental factors), acute care, and rehabilitation need to be urgently implemented across all countries to reduce stroke burden" (Feigin et al., 2024). That is diplomatic language for: we are losing ground.

The Young Are Not Safe

Perhaps the most disturbing finding is the rise in stroke among people under 70. The authors found that incidence, death, and DALY rates increased in this age group in several regions. This is not just a statistical artifact of aging populations. It is a real increase in the rate of stroke among younger adults.

Why? The usual suspects: obesity, diabetes, high blood pressure, and sedentary lifestyles are now common in younger cohorts. The metabolic damage that used to take decades to accumulate is now appearing earlier. And once a young person has a stroke, they face decades of disability.

What This Actually Means

• ▸The war on stroke is not over. It has entered a new phase where the enemy is not just blood pressure and smoking, but obesity, climate change, and metabolic disease. Prevention strategies must be updated to reflect this.

• ▸High BMI is the single biggest driver of the rising stroke burden. This is not a problem that can be solved with posters in doctors offices. It requires systemic changes in food environments, urban design, and economic incentives.

• ▸Climate change is a stroke risk factor. High ambient temperature increases stroke burden by 72%. As heat waves become more frequent and intense, stroke rates will likely rise further. Health systems need to prepare.

• ▸The global disparities are widening. Low and middle income countries are bearing the brunt of the stroke burden, and they have the least resources to address it. International funding for stroke prevention and treatment needs to increase.

• ▸Stroke is becoming a disease of the young. If you are under 70 and think stroke cannot happen to you, the data says otherwise. Prevention starts early.

• ▸The stagnation after 2015 is a warning sign. The easy gains from smoking cessation and blood pressure control may have been harvested. The remaining risk factors are harder to change. We need new tools.

• ▸Surveillance matters. Without accurate, timely data on stroke incidence and risk factors, we are flying blind. The authors call for better stroke registries, especially in low income countries. That is not a luxury. It is a necessity.

Stroke is not going away. It is evolving. And we are not evolving fast enough to keep up.