Pre-diabetes is much more common than you might think: Diabetes expert Dr. Tim Graham says about forty percent of Americans are pre-diabetic and less than ten percent of those people even know they have it. Pre-diabetes doesn’t have any symptoms, and sometimes it affects even people with healthy habits and a good BMI. But the good news is pre-diabetes is reversible. Dr. Graham talks about what it means to have pre-diabetes and what you can do to prevent it from worsening.