Blood Glucose

Source: MedlinePlus Health Topics, U.S. National Library of Medicine

Last synced 8/9/2026Status: primary verified

What is blood glucose? Blood glucose, or blood sugar, is the main sugar found in your blood. It is your body's primary source of energy. It comes from the food you eat. Your body breaks down most of that food into glucose and releases it into your bloodstream. When your blood glucose goes up, it signals your pancreas to release insulin. Insulin is a hormone that helps the glucose get into your cells to be used for energy. What is diabetes? Diabetes is a disease in which your blood glucose levels are too high. When you have diabetes, your body doesn't make enough insulin, can't use it as well as it should, or both. Too much glucose stays in your blood and doesn't reach your cells. Over time, having too much glucose in your blood can cause serious health problems (diabetes complications). So if you have diabetes, it's important to keep your blood glucose levels within your target range. What are blood glucose targets? If you have diabetes, your blood glucose target is the range you try to reach as much as possible. The typical targets are: Before a meal: 80 to 130 mg/dL Two hours after the start of a meal: Less than 180 mg/dL Your blood glucose targets may be different, depending on your age, any additional health problems you have, and other factors. Talk with your health care team about the best target range for you. When and how should I check my blood glucose? If you have diabetes, you'll likely need to check your blood glucose every day to make sure that your blood glucose numbers are in your target range. Some people may need to check their blood glucose several times a day. Ask your health care team how often you need to check it. The most common way to check your blood glucose level at home is with a blood glucose meter. A blood glucose meter measures the amount of glucose in a small sample of blood, usually from your fingertip. Continuous glucose monitoring (CGM) is another way to check your glucose levels. Most CGM systems use a tiny sensor that is inserted

Educational only

This information is for general education and is not medical advice. Always talk to a licensed U.S. clinician about your situation, medications, or treatment decisions.