Medically Reviewed By: Tom Iarocci, MD

For people with diabetes, the aim of treatment is generally to bring the blood sugar, or blood glucose, down as close to the "normal" levels as possible. However, in order to make sure that your treatment is working for you, you will need to begin by learning about normal blood sugar levels for adults with diabetes, and how you can achieve them.

What Is Blood Sugar?

First of all, it's important to know the difference between glucose and sugar. Sugar is the general term for a sweet carbohydrate that can dissolve in water. There are many different types of sugar, and the one that the body uses the most is known as glucose. When you hear people talking about blood sugar, they are generally talking about blood glucose.

Normal Blood Glucose:

The normal blood sugar level for adults with diabetes will be measured differently depending on your geography. For example, in the United States, blood sugar is typically measured in mg of glucose per deciliter of blood (mg/dl). On the other hand, in the United Kingdom and Canada, blood sugar can be measured in millimoles.

What Are Normal Blood Sugar Levels for Nonpregnant Adults with Diabetes?

Normal blood sugar numbers depend on the time of day and how recently you had a meal, in addition to a variety of other factors. For someone who doesn't have diabetes, a fasting blood sugar level on awakening (no food in the last 8-12 hours) should usually be under 100 mg/dl, whereas before-meal levels would be 70-99 mg/dl, and levels two hours after meals (called post-prandial levels) should be under 140 mg/dl. A level of 100 to 125 mg/dL means you have impaired fasting glucose, a type of prediabetes. This increases your risk of developing type 2 diabetes.

Of course, blood sugar levels for adults with diabetes are often quite different from the levels for people without diabetes. If you have diabetes, your blood sugar might not ever be 100 percent normal all the time, but you and your doctor will work to get your levels as close to normal as possible. If you do have diabetes, then the American Diabetes Association generally suggests that you should work to keep your blood sugar levels before meals between 80-130 mg/dl, and your levels after meals under 180 mg/dl. However, target ranges are individual; what is appropriate for one person with diabetes may not be appropriate for another. Many patients and their doctors will attempt to shoot for levels that are very close to those seen in people without diabetes.

Although lower numbers in your blood sugar levels can be difficult to achieve, and can require more frequent monitoring and careful diet considerations, they are generally better at protecting you against complications, so long as you don’t go too low.

Normal Blood Sugar Levels Over The Long Term:

In addition to the more real-time blood sugar tests with finger sticks, there is a test called HbA1c, or simply A1c, that gives you and your doctor a picture of what your blood sugars have been doing, on average, over the last 3 months. The amount is expressed as a percentage, and a person without diabetes generally has A1c levels at below 5.7%. The targets for a person with diabetes are usually 7.0% or lower. Again, goals are individual, and certain older people with diabetes who have other health conditions might be managed differently with respect to a target A1c.

Much of the risk from diabetes comes from this long-term exposure to blood sugar levels that have risen above normal. The excess exposure to these sugar molecules in your blood can cause changes in the body that affect the nerves, blood vessels, and key organs such as the heart, brain, kidneys and eyes. This can lead to diabetes-based complications.

People with diabetes need help to keep sugars within the normal range. On the other hand, blood sugar levels that are allowed to go too low can also cause problems, including fainting, confusion, dizziness and increased risk of a fall.