When doctors are talking about blood sugar, what they really talking about?

Okay so basically,
They are talking about type 2 Diabetes, Probably trying to warn you.

Having diabetes means the glucose (sugar) levels in your blood are too high. Diabetes is a chronic (long-term) condition.

You're more likely to get type 2 diabetes if you're over age 45, you're overweight, or you have prediabetes. People with prediabetes have blood glucose levels higher than normal, but not high enough to be diagnosed with type 2 diabetes. Having prediabetes increases your risk for type 2 diabetes, heart disease, and stroke.

Diabetes is a leading cause of disability and death in the United States. The good news is that you can do a lot to prevent or delay type 2 diabetes, including:

Watching your weight
Eating healthy
Staying active.
Hope this helps <3!