Blood glucose (blood sugar)
The sugar carried in your blood as fuel for your cells: measured in mg/dL or mmol/L.
Blood glucose is the amount of sugar circulating in your bloodstream at a given moment, the body's main quick-access energy source. It rises after eating carbohydrate and falls as insulin moves that glucose into cells.
It's reported in mg/dL (common in the US) or mmol/L (most of the rest of the world); the two differ by a factor of about 18. Keeping it within a target band most of the day is the goal behind time in range.