Insulin Safety Center

Understanding blood sugar

Blood sugar can be measured at any time of day.  Understanding blood sugar can be hard, but it doesn't have to be!

Information you need to know:

  1. It is important to know (and write down) what time of day you measured your blood sugar (for example, 3:15 PM).
  2. Also, write down how much time has passed since you last ate and drank (for example, "ate a turkey and cheese sandwich on white bread 2 hours ago").

Keep track of time

Knowing time of day and recent foods/drinks will help you understand your blood sugar.

"Fasting" Blood Sugar...just a shapshot of your blood sugar control on an empty stomach

If you have not eaten for 8 hours or more, this is called a "fasting" blood sugar. In people without diabetes, "fasting" blood sugar is usually between 70 and 110 (mg/dL).

What is my "fasting" blood sugar goal?
The goal for "fasting" blood sugar is often to be between 80 and 130 (mg/dL). Ask your doctor what your goal is.

There is a way to measure your long-term blood sugar control. It's called A1c. A1c is short for hemoglobin A1c. A1c measures your sugar control over 3 months.

What is my A1c goal?

Below 6.5

"Post-Prandial" Blood Sugar...a shapshot of your mealtime blood sugar control

If you ate a meal about 2 hours ago, this is called a "2-hour post-prandial" blood sugar. In people without diabetes, blood sugar is highest 1 hour after eating and is usually less than 140 (mg/dL). What is my "post-prandial" blood sugar goal? The goal for "2-hour post-prandial" blood sugar is often to be less than 180 (mg/dL). Ask your doctor what your goal is.

• 1-2 hours after beginning of the meal (post-prandial blood sugar)*: Less than 180 mg/dL

A1c...It's like a 3-month video of your blood sugar control

The goal for most adults with diabetes is an A1C that is less than 7%.

Results give you a picture of your average blood sugar level over the past two to three months. The higher the levels, the greater your risk of developing diabetes complications.