Glossary

Time in Range (TIR)

The percentage of your CGM readings that fall inside the target range of 70–180 mg/dL, with the international consensus goal being above 70%.

A1C (HbA1c)

A blood test measuring the percentage of hemoglobin coated in glucose, reflecting your average blood sugar over roughly the past three months.

Glycemic index (GI)

A 0–100 scale ranking how quickly a food's carbs raise blood glucose, with pure glucose set at 100.

Glycemic load (GL)

A measure combining a food's glycemic index with its actual carb amount per serving — speed times quantity.

Net carbs

Total carbohydrates minus fiber (and sometimes sugar alcohols) — an estimate of the carbs that actually raise blood glucose.

Bolus

A dose of rapid-acting insulin taken for a specific purpose — covering the carbs in a meal or correcting a high reading.

Basal insulin

The background insulin that covers your body's glucose output between meals and overnight, separate from mealtime doses.

Insulin-to-carb ratio (I:C)

Your personal ratio describing how many grams of carbohydrate one unit of rapid-acting insulin covers, used to size meal doses.

Correction factor (ISF)

Your personal number for how many mg/dL one unit of rapid-acting insulin lowers your blood glucose, also called insulin sensitivity factor.

CGM (continuous glucose monitor)

A wearable sensor that measures glucose every few minutes around the clock, showing your level, trend, and history in real time.

Pre-bolus

Taking your mealtime insulin some minutes before eating so its action lines up with the food's glucose arrival.

Dawn phenomenon

An early-morning rise in blood glucose caused by natural hormone surges, typically showing up between about 3am and 8am.