A1C is a blood test for type 2 diabetes and prediabetes. It measures your average blood glucose, or blood sugar, level over the past 3 months. Doctors may use the A1C alone or in combination with other diabetes tests to make a diagnosis. They also use the A1C to see how well you are managing your diabetes. This test is different from the blood sugar checks that people with diabetes do every day.
Your A1C test result is given in percentages. The higher the percentage, the higher your blood sugar levels have been:
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
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:
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 under your skin. The sensor measures your glucose level every few minutes. It can show changes in your glucose level throughout the day and night. A CGM system is especially useful for people who take insulin and have problems with low blood glucose.
Your provider will also check your blood glucose with a blood test called an A1C. It checks your average blood glucose level over the past three months. People with diabetes usually have an A1C test at least twice a year. But you may need the test more often if you aren't meeting your diabetes treatment goals.
What happens if my blood glucose level becomes too high?High blood glucose is called hyperglycemia. Symptoms that your blood glucose levels may be too high include:
If you often have high blood glucose levels or symptoms of high blood glucose, talk with your health care team. You may need a change in your diabetes meal plan, physical activity plan, or diabetes medicines.
High blood glucose may also be caused by other conditions that can affect insulin or glucose levels in your blood. These conditions include problems with your pancreas or adrenal glands.
What happens if my blood glucose level becomes low for me?Hypoglycemia, also called low blood glucose, happens when your blood glucose level drops below what is healthy for you. For many people with diabetes, this means a blood glucose reading lower than 70 mg/dL. Your number might be different, so check with your health care team to find out what blood glucose level is low for you.
Symptoms of low blood glucose tend to come on quickly. The symptoms can be different for everyone, but they may include:
Low blood glucose levels can be common in people with type 1 diabetes and people with type 2 diabetes who take certain diabetes medicines. If you think you may have low blood glucose, check your level, even if you don't have symptoms. Low blood glucose can be dangerous and should be treated as soon as possible.
Although it's rare, you can still get low blood glucose without having diabetes. The causes can include conditions such as liver disease, kidney disease, and hormone deficiencies (lack of certain hormones). Some medicines, such as certain heart medicines and antibiotics, can also cause it. See your provider to find out the cause of your low blood glucose and how to treat it.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
Diabetes is a disease in which your blood glucose, or blood sugar, levels are too high. Glucose comes from the foods you eat. Insulin is a hormone that helps the glucose get into your cells to give them energy. With type 1 diabetes, your body does not make insulin. With type 2 diabetes, the more common type, your body does not make or use insulin well. Without enough insulin, the glucose stays in your blood. You can also have prediabetes. This means that your blood sugar is higher than normal but not high enough to be called diabetes. Having prediabetes puts you at a higher risk of getting type 2 diabetes.
Over time, having too much glucose in your blood can cause serious problems. It can damage your eyes, kidneys, and nerves. Diabetes can also cause heart disease, stroke and even the need to remove a limb. Pregnant women can also get diabetes, called gestational diabetes.
Blood tests can show if you have diabetes. One type of test, the A1C, can also check on how you are managing your diabetes. Exercise, weight control and sticking to your meal plan can help control your diabetes. You should also monitor your blood glucose level and take medicine if prescribed.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
What is prediabetes?
Prediabetes means that your blood glucose, or blood sugar, levels are higher than normal but not high enough to be called diabetes. Glucose comes from the foods you eat. Too much glucose in your blood can damage your body over time.
If you have prediabetes, you are more likely to develop type 2 diabetes, heart disease, and stroke. But if you make some lifestyle changes now, you may be able to delay or prevent type 2 diabetes.
What causes prediabetes?Prediabetes usually happens when your body has a problem with insulin. Insulin is a hormone that helps the glucose get into your cells to give them energy. A problem with insulin could be:
Researchers think that being overweight and not getting regular physical activity are major factors in causing prediabetes.
Who is at risk for prediabetes?About 1 out of every 3 adults has prediabetes. It is more common in people who:
Most people don't know they have prediabetes because usually there are no symptoms.
Some people with prediabetes may have darkened skin in the armpit or on the back and sides of the neck. They may also have many small skin growths in those same areas.
How is prediabetes diagnosed?There are a few different blood tests that can diagnose prediabetes. The most common ones are:
If you have prediabetes, you may be able to delay or prevent type 2 diabetes through lifestyle changes:
In some cases, your health care provider may also recommend taking diabetes medicines.
Can prediabetes be prevented?If you are at risk for prediabetes, those same lifestyle changes (losing weight, regular physical activity, and a healthy eating plan) may prevent you from getting it.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
Until recently, the common type of diabetes in children and teens was type 1. It was called juvenile diabetes. With Type 1 diabetes, the pancreas does not make insulin. Insulin is a hormone that helps glucose,or sugar, get into your cells to give them energy. Without insulin, too much sugar stays in the blood.
Now younger people are also getting type 2 diabetes. Type 2 diabetes used to be called adult-onset diabetes. But now it is becoming more common in children and teens, due to more obesity. With Type 2 diabetes, the body does not make or use insulin well.
Children have a higher risk of type 2 diabetes if they are overweight or have obesity, have a family history of diabetes, or are not active. Children who are African American, Hispanic, Native American/Alaska Native, Asian American, or Pacific Islander also have a higher risk. To lower the risk of type 2 diabetes in children:
Children and teens with type 1 diabetes may need to take insulin. Type 2 diabetes may be controlled with diet and exercise. If not, patients will need to take oral diabetes medicines or insulin. A blood test called the A1C can check on how you are managing your diabetes.