Leading Causes of Death in America: What Kills the Most People

Two diseases — heart disease and cancer — together account for nearly half of all deaths in the United States, and have for decades. But behind those two giants, the rankings have been shifting: unintentional injuries (driven largely by drug overdoses) and Alzheimer's disease have climbed sharply, while stroke and others have eased. This guide ranks the leading causes of U.S. death and shows how the picture has changed over time.

What do Americans die of?

The bar chart ranks the leading causes of death by number of lives lost in a year. Heart disease and cancer tower over the rest — each kills far more Americans than anything else, and together they cause close to half of all deaths. After that, a cluster of causes — accidents, chronic lower respiratory diseases (CLRD), stroke, Alzheimer's, and diabetes — fill out the top ranks, each responsible for tens of thousands of deaths a year.

Heart disease and cancer dominate

For decades, heart disease has been America's number-one killer and cancer its number two. The encouraging news is that the rates of both have fallen substantially over time, thanks to less smoking, better screening, and improved treatment — so even as the population grows and ages, deaths per capita from these diseases have declined. They remain dominant simply because they are so common across an aging society.

The rise of accidents and Alzheimer's

The trend chart reveals the real story of change. Unintentional injuries (accidents) climbed sharply, propelled largely by the drug-overdose epidemic, rising from a distant cause to one of the leading killers of Americans. Alzheimer's disease deaths also rose steeply, as the population ages and the condition is more often recorded as a cause of death. Meanwhile stroke, once the third-leading cause, has eased thanks to better prevention and treatment of high blood pressure.

What the numbers don't show

One important caveat: this data runs through 2017, so it predates the COVID-19 pandemic, which temporarily became a leading cause of death in 2020 and 2021 before receding. The rankings also reflect recorded causes, which can shift with changes in diagnosis and reporting. Still, the big picture is durable: chronic diseases of an aging, affluent society — heart disease, cancer — dominate, while "deaths of despair" like overdoses have reshaped the ranks beneath them.