​Heart disease and stroke are the first and third leading causes of death in the United States, respectively. They are the principal components of cardiovascular disease, accounting for nearly 40% of all deaths. That's more than the next six leading causes of death combined. About 950,000 Americans die of cardiovascular disease each year, which amounts to one death every 33 seconds.

Many people don't know the warning signs or how to prevent a stroke or heart attack. Take a few minutes and learn more about the nation's leading killers.