Testing Your Blood Sugar

When it comes to controlling your diabetes, knowing your blood sugar (also called blood glucose) numbers is important. Keeping track of your blood glucose helps you see how food, physical activity, and medicine affect your blood glucose levels.

Blood glucose monitoring

If you take insulin, you will most likely need to check your own blood sugar. To do this, you'll use a device called a blood glucose meter or blood glucose monitor. This simple device measures the glucose in the drop of blood you provide. Learn more about how to check your blood sugar.

Blood sugar levels change throughout the day

There are 2 terms you will hear when testing your blood sugar levels:

• Fasting blood glucose is your blood sugar level after you have not eaten for 8 to 12 hours (usually overnight)
• Postprandial glucose is your blood sugar level taken 1 to 2 hours after you have eaten

The readings from your blood glucose meter can help you understand your insulin needs for these different times of the day. The chart below shows the expected range of glucose levels in plasma.

People with diabetes often test blood glucose before and after meals. They may also check at bedtime. To know more about how often to check your blood glucose, consult with your doctor.

You should also keep a record of your blood glucose monitor readings and review them during doctor visits. To get started, use this easy-to-use blood sugar diary.

Nocturnal hypoglycemia

One reason to monitor blood glucose levels is that, when your blood glucose levels go down overnight, you may be at risk for a condition called nighttime or nocturnal hypoglycemia, or low blood sugar. This is particularly dangerous because, while asleep, you may not know that this is happening. Hypoglycemia can also become more serious and even lead to coma or death, so itʼs important that you and your doctor understand how—and when—your body is using blood sugar.

Hyperglycemia, or high blood sugar, can also be a problem for some people with diabetes. Symptoms of hyperglycemia may include having to urinate often, being very thirsty, and losing weight. Talk to your doctor to find out more about testing your blood levels, and what levels will be healthy for you.

The A1C test

An A1C test is a blood sugar test that helps you and your doctor understand how well your treatment plan is working over time. For this test, you will provide a small blood sample, which will be tested in a lab. The results from the A1C test will show your blood glucose level over the last 3 months.

This chart shows the range of A1C test results. Discuss your A1C test score with your doctor to find the A1C goal that's right for you.

The ADA recommends that your A1C be less than 7. If your result is 7 or more, it may be necessary to change your treatment plan in order to manage your diabetes more effectively. Learn more about knowing your A1C.