Are reactive hypoglycemia and pre-diabetes the same thing?

1 is type of other: They aren't quite the same thing. There are many types of pre-diabetes - which is any condition or indication that you might develop diabetes (chronically high blood sugar) later on. Oddly enough, reactive hypoglycemia (low blood sugar after eating)- or any hypoglycemia for that matter- is a risk factor for developing diabetes. Other pre-diabetic types: impaired glucose tolerance & fasting glucose

Different.: These are different things. Reactive hypoglycemia is an overly brisk response of your pancreas to a particularly sugary meal; too much insulin is released in the blood sugars plummet. Prediabetes is a slight elevation of your blood sugars in the longer-term which suggests a predisposition to diabetes.