According to the Centers for Disease Control and Prevention, more than 30.3 million people in the U.S. have diabetes. Another 84.1 million have pre-diabetes, a condition that can lead to type 2 diabetes within five years, if it's not treated. Diabetes is a major risk factor for early death from heart attack, stroke and many cancers. It also increases the risk of kidney disease, blindness and amputation. But these outcomes are not inevitable, if you learn about the disease and your role in managing it.