The AHA has grown into the nation’s oldest and largest voluntary organization dedicated to fighting heart disease and stroke. A shared focus on cardiovascular health unites our more than 33 million volunteers and supporters as well as our more than 3,400 employees. Heart disease is the No. 1 killer worldwide, and stroke ranks second globally. Even when those conditions don’t result in death, they cause disability and diminish quality of life. We want to see a world free of cardiovascular diseases and stroke.