For diabetics, knowing their blood glucose numbers is crucial.

What is Blood Glucose?

A blood glucose test measures the amount of a type of sugar, called glucose, in your blood. Glucose comes from carbohydrate foods. It is the main source of energy used by the body. Insulin is a hormone that helps your body's cells use the glucose. Insulin is produced in the pancreas and released into the blood when the amount of glucose in the blood rises.

Normally, your blood glucose levels increase slightly after you eat. This increase causes your pancreas to release insulin so that your blood glucose levels do not get too high. Blood glucose levels that remain high over time can damage your eyes, kidneys, nerves, and blood vessels. People with diabetes must continually monitor blood glucose to ensure they get the proper treatment for diabetes.

There are Two Tests to Measure your Blood Glucose

The A1C test reflects average blood glucose level over the last 3 months. A small blood sample to check your A1C can be taken at any time of the day.

The A1C test is the best test for you and your health care team to know how well your treatment plan is working over time. The test shows if your blood glucose levels have been close to normal or too high. The higher the amount of glucose in your blood, the higher your A1C result will be. A high A1C result will increase your chances for serious health problems.

You and your health care team should discuss the A1C goal that is right for you. For most people with diabetes, the A1C goal is less than 7. An A1C higher than 7 means that you have a greater chance of eye disease, kidney disease, or nerve damage. Lowering your A1C—by any amount— can improve your chances of staying healthy.

Ask for an A1C test at least twice a year. Get the test more often if your blood glucose stays too high or if your treatment plan changes.

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The blood glucose test you do yourself uses a drop of blood and a meter that measures the level of glucose in your blood at the time you do the test. This is called self-monitoring of blood glucose (SMBG). to ensure accuracy, buy a blood glucose monitor that is high-quality and reliable.

Self monitoring of blood glucose with a meter helps you see how food, physical activity, and medicine affect your blood glucose levels. The readings you get can help you manage your diabetes day by day or even hour by hour. Keep a record of your test results and review it at each visit with your health care team.

To do SMBG, you use a tiny drop of blood and a meter to measure your blood glucose level. Be sure you know how to do the test the correct way. Also, ask your health care team whether your meter gives the results as plasma or whole blood glucose. Most new meters provide the results as plasma glucose.

  • Before meals: Plasma value of 90-130 and Whole blood value of 80-120
  • One or two hours after a meal: Plasma value of less 180 and whole blood value of less than 170.

Self-tests are usually done before meals, after meals, and/or at bedtime. People who take insulin usually need to test more often than those who do not take insulin. Ask your health care team when and how often you need to check your blood glucose.