In 2012, 86 million Americans over the age of 20 had prediabetes. Before people develop Type 2 diabetes, they almost always have "prediabetes" — blood glucose levels that are higher than normal but not yet high enough to be diagnosed as diabetes. People with prediabetes often have no symptoms. Through early diagnosis and prevention, many people with prediabetes can delay or even prevent the onset of Type 2 diabetes.