About Diabetes

Blood Glucose and Insulin

Understanding how glucose and insulin work in your body is the foundation for knowing how diabetes works. By knowing what can affect your blood glucose (blood sugar) levels, you can better manage it.

The basics of high blood glucose

Diabetes is a problem with your body that causes blood glucose levels to rise higher than normal. This is also called hyperglycemia.

When you eat, your body breaks food down into glucose and sends it into the blood. Insulin then helps move the glucose from the blood into your cells. When glucose enters your cells, it is either used as fuel for energy right away or stored for later use. In a person with diabetes, there is a problem with insulin. But, not everyone with diabetes has the same problem. 

There are different types of diabetes—type 1, type 2 and gestational diabetes. If you have diabetes—type 1, type 2 or gestational—your body either doesn't make enough insulin, can't use the insulin well, or both.


Learn more about blood glucose     Learn more about insulin

So, what affects my blood glucose levels?

It is important to understand what can make your blood glucose rise or fall, so that you can take steps to stay on target.

Things that can make blood glucose rise include:

  • A meal or snack with more food or more carbohydrates than usual
  • Inactivity
  • Side effects of medications
  • Infection or other illness
  • Changes in hormone levels, such as during menstrual periods
  • Stress

Things that can make blood glucose fall include:

  • A meal or snack with less food or fewer carbohydrates than usual
  • Extra activity
  • Side effects of other medications
  • Missing a meal or snack
  • Drinking alcoholic beverages (especially on an empty stomach)

Find out about tests for diabetes