What is meant by the term excursion in diabetes patients?

“Excursion” simply means fluctuations in your blood sugar, but the term is usually used when talking about how much the blood sugar numbers change with meals. Doctors will say that your meal-related “excursions” shouldn’t be more than a certain number. For example, I often tell my patients that an excursion of no more than 40 to 60 mg/dL glucose with a meal indicates very good control. An example would be a person whose pre-meal number is around 90 with a rise to about 140 maximum after eating. That would qualify as an “excursion” of 50 points -- pretty close to the kind of change you would see in someone without diabetes. The concept is also helpful in knowing whether someone has a problem with blood sugar control primarily in the fasting setting or after eating. 

For example, let’s say a person takes a combination of long- and short-acting insulin and she has a hemoglobin A1c of 8.5. She needs to do better, but should there be adjustment to the long-acting insulin, the short-acting insulin or both? Well, if the fasting or pre-meal glucose levels are high (let’s say around 220) but the meal-related excursions are typically only around 50 mg/dL (from about 220 to about 270 on average), then you know that the fast-acting insulin doses are generally correct, but the long-acting insulin dose is too low. If the person took enough long-acting insulin to get the fasting sugar down to around 100, then with meals that 50 point excursion would be just about perfect.