It is too much sugar in your blood that is bad. For perspective, “normal” blood sugar levels are those considered to be below 100 mg/dL. Kidney damage starts at an average blood sugar of 212 mg/dL. So we can pretty much agree that below 100 is OK and above 212 is bad. But what about in between?
Well, that’s where the devil is in the details.
Blood sugar comes in several flavors, as it were. We can talk about fasting blood sugar, which is the level of sugar in your blood when it has been some time since you last ate. We can talk about postprandial blood sugar, which is several hours after eating. We can talk about peak excursions, which is the maximum blood sugar level following a meal. And we can talk about average blood sugars, which is a mathematical look at where you are overall most of the time.
Each one of these kinds of blood sugars have different targets. A target is simply a good place to keep your blood sugar in most of the time to keep your body safe over the long run.
For people with diabetes, the trick is to combine medication, activity, and diet to hit those target numbers as often as humanly possible, while realizing that you can’t do it all of the time.
Different doctors may choose different targets depending on your age, overall health, and host of other factors, but typical targets for fasting blood sugar are 90-115 mg/dL and for postprandial 150-180. As to excursions, no one likes to see numbers over 275 mg/dL. For averages we want you under 151 mg/dL.
So readings above any of those targets might be considered “bad;” but I want to point out that there is really no such thing as a “bad” number. A high number is actually very good information. It is nature’s way of telling you that your blood sugar is getting to a point where it could hurt you. In short, “bad” numbers are simply good information that need to be acted on.
