How Your Body Uses Glucose and Insulin

About Insulin and High Blood Glucose

Diabetes is a problem with your body t hat causes blood glucose (also called blood sugar) 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, your body either doesn't make enough insulin, can't use insulin it does make well, or both.

Type 1

in type 1 diabetes, your immune system mistakenly treats the beta cells in your pancreas that make insulin as foreign invaders and destroys them. This can happen over a few weeks, months, or years.

When enough beta cells are gone, your pancreas stops making insulin, or makes so little insulin that you need to take insulin to live. Type 1 diabetes develops most often in young people but can appear in adults. 

Type 2

If you have type 2 diabetes your body does not use insulin properly. This is called insulin resistance. At first, the beta cells make extra insulin to make up for it. But, over time your pancreas can't make enough insulin to keep your blood glucose at normal levels. Type 2 diabetes develops most often in middle aged and older adults but can appear in young people.

Some people can with type 2 diabetes can manage their diabetes with healthy eating and exercise. However, your doctor may need to also prescribe oral medications (pills) and/or insulin to help you meet your target blood glucose levels. Diabetes is a progressive disease. Even if you don't need to treat your diabetes with medications at first, you may need to over time. 

Gestational Diabetes

Gestational diabetes is diabetes that develops during pregnancy. For most women, blood glucose levels will return to normal after giving birth. If you've had GDM you will need to be tested regularly since you are at much higher risk for developing type 2 diabetes later in life. 

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:

  • 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:

  • 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

  • Last Reviewed: October 7, 2009
  • Last Edited: August 30, 2018

Articles from Diabetes Forecast® magazine:

Diabetes Forecast