Hemoglobin (Hgb) Test for Diabetes

The Hgb test is used as a test to diagnose prediabetes and diabetes, and is also used to manage long-term blood sugar for diabetics.
Hemoglobin (Hgb) Test for Diabetes
Natalie Stein

Exercise, Fitness & Nutrition Expert | Lark Health

What is the Hgb Test?

A hemoglobin (Hgb) test is a blood test that measures your average blood sugar level over the last 3 months. It specifically measures how much hemoglobin is in your red blood cells.

This test is often referred to as the A1C test, hemoglobin A1C, or the HbA1c test. It is used as a test to diagnose prediabetes and diabetes, and is also used to manage long-term blood sugar for those with diabetes.

What is Hemoglobin?

Hemoglobin is a protein in healthy red blood cells, and is created in your bone marrow. Its job is to deliver oxygen to the cells of your body from your lungs, and bring carbon dioxide back to be replenished with oxygen.

The amount of hemoglobin in your red blood cells is important to monitor. Too much or too little hemoglobin can cause weakness, shortness of breath, dizziness, headaches, and a pounding sound in your ears.

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What is an Hgb Test For?

The hemoglobin test for diabetes could be one of the most important medical tests you get. The test, more accurately known as a glycated hemoglobin or A1C test, is closely related to blood sugar levels.

It is used for diabetes diagnosis and management. You may use an A1C test for diabetes if you have risk factors for diabetes or you have diabetes. 

Here is what you should know about the glycated hemoglobin test for diabetes.

Table Of Contents

What is the Hemoglobin (Hgb) Test?

A hemoglobin test checks for glucose bound to hemoglobin and tells you your average blood sugar. The test is a simple blood test that you can get at almost any lab. Just ask your doctor or call ahead to be sure that you can get your A1C test at your regular lab.

Your doctor will take a sample of blood either by drawing blood using a needle, or by pricking your finger. Unlike for a regular blood sugar test, you do not need to fast for your test. 

You will get the results within days or weeks, as you normally do with your doctor and lab. Your doctor should help you understand the results if you have questions.

Symptoms of High Levels of Hemoglobin

Low levels of hemoglobin can cause the following symptoms, which can be difficult to spot:

  • Shortness of breath
  • Dizziness
  • Headache
  • Pale skin
  • Cold hand and feet
  • Low body temperature
  • Rapid heartbeat

If you think you may match any of these symptoms, call your doctor to schedule an A1C test.

Signs You May Need to Test Your A1C

Your doctor may order an A1C test if you:

  • Are overweight or obese
  • Are an older adult
  • Physically inactive
  • Have a family history of diabetes
  • Show symptoms of diabetes, such as excessive thirst or urination, unexplained weight loss or fatigue, blurred vision, or darkened skin on the back of your neck.
  • Have had a baby weighing over 9 pounds (which is a sign of gestational diabetes). You should get your A1C tested every 3 years if you had gestational diabetes during pregnancy.

Another reason why your doctor might want an A1C test to diagnose prediabetes or diabetes is to confirm the results of a previous A1C test that came back high. The American Diabetes Association (ADA) suggests getting a second test on a different day before diagnosing prediabetes or diabetes.

Are you unsure whether you have diabetes, prediabetes, or risk factors? If you are not sure, you might want to ask your doctor about an A1C test for blood sugar. You can easily have high blood sugar without feeling any signs.

A1C Chart – What Do My Results Mean?

Here is an A1C chart can help you understand the results of your glycated hemoglobin test for diabetes:

Category HbA1C Values Estimated Average Glucose (eAG)
At least 6.4%
At least 137 mg/dl
5.7 to 6.4%
117 to137 mg/dl
Less than 5.7%
Less than 117 mg/dl

High A1C and Diabetes

Diabetes is the real reason to pay attention to high A1C. A high value is a sign of high blood sugar levels, as you know from seeing the link to estimated average glucose over the past 3 months. Slightly above-normal blood glucose means prediabetes, and blood sugar levels above that mean that you have diabetes.

Your A1C test results can give you a glimpse of something else, too. Just as blood glucose binds to your hemoglobin and impairs their function, it binds to other proteins in your blood and makes them less healthy, too. If your glycated hemoglobin percentage is higher than normal, you are likely to have higher-than-normal glycation and associated health problems in the following areas:[2]

What is a Goal A1C?

Your goal A1C range depends on your health status and personal factors. Your goal is lowest if you do not have diabetes, and highest if you have diabetes and additional complicating factors. What your A1C should be also considers your individual factors, such as your lifestyle, your treatment and management preferences, and how long you have had diabetes.

A1c Blood Chart Goal Ranges

This A1C normal range chart shows that your HbA1C normal range can vary depending on your age and gender.

Situation A1C Goal
Healthy, no prediabetes or diabetes
Less than 5.7%
Less than 5.7% (reverse prediabetes) or 6.4% (prevent type 2 diabetes)
Diabetes with intensive lifestyle change (e.g., weight loss and physical activity)
No more than 6.5%
Diabetes, without additional risk factors
Under 7%
Diabetes, with additional risk factors such as older age, extensive comorbidities, or trouble controlling blood sugar
Under 8%
YOU with your own individual situation
Talk to your doctor!

How to Lower A1C

You can work towards healthy A1C levels if your test is not in the normal HbA1C range. Healthy lifestyle changes can lower your glycated hemoglobin level if you have prediabetes or your glycosylated hemoglobin test shows that you have diabetes.

Your doctor may have been suggesting for years that you lose weight if you are carrying around extra pounds. There are plenty of reasons to lose weight, and achieving an HbA1C in the normal range is one of them. Each pound that you lose has real effects on your blood sugar levels and health. 

Do you think of restriction and starvation when you think of weight loss? You do not need to. Instead, you might find it easier to lose weight and keep it off with more positive strategies. For example…

  • Eat more. Specifically, eat more non-starchy vegetables because they are low-calorie and filling. Aim to fill half your plate or bowl with vegetables at most meals and snacks.
  • Meet the guidelines. Most Americans should increase their intake of healthy foods such as vegetables, fruit, fish, beans, whole grains, and nuts. As you work to increase those foods, you may end up reducing other, less healthful foods.
  • Eat for fullness. Choose more fiber and lean protein. You will not only get a lower-calorie, more filling meal, but you will have less of a blood sugar swing and stay fuller for longer after your meal.
  • Use a health coaching app. Personalized support, feedback, and tracking food and weight can all help you lose weight.

The other most important step that can lower A1C is to take steps, literally. Exercise increases insulin sensitivity and lowers blood sugar. These guidelines can help you get into an exercise routine.

  • Aim for 30 minutes, most days of the week. You may need to start with much less and work up gradually.
  • You do not have to do 30 minutes at once. You can try 5 or 10-minute increments if that is more convenient for you.
  • Walking, swimming, dancing, and tennis all count. So do gardening, kickboxing, rowing, and aerobics. Anything that gets your heart rate up works.
  • Check with your doctor before starting an exercise program.
  • Consider using a health coaching app for motivation, tracking, reminders, and goal-setting.

Other ways to lower hemoglobin include:

  • Managing stress
  • Getting adequate sleep
  • Eating a moderate amount of carbs at most meals and snacks instead of having them all at once

How to Lower A1C with Medications and Monitoring

Insulin or oral medications for diabetes can get your A1C values down. If your doctor has prescribed one or more medications for you, be sure to take them exactly as prescribed. Your hemoglobin A1C levels may stay high if you skip doses, take them at the wrong times, or take different doses. A digital health coach can help you keep track of your medication use.

Monitoring your blood glucose levels does not directly lower your A1C results, but it can help indirectly as it keeps you on top of your diabetes. When you measure blood glucose one or more times daily, as your healthcare provider suggests, you can identify patterns and figure out what lowers or raises your blood sugar. Since glycated hemoglobin reflects your blood sugar over a few months, your next A1C blood test results may be lower if you have lowered your blood glucose.

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Why Hgb Tests Matter

If you think you have any of the signs or symptoms of a high or low A1C, contact your doctor to be tested immediately. By catching a high reading earlier, you can take steps to correcting it and even prevent type 2 diabetes.

These healthy lifestyle changes can be a lot to think about, but there is no need to get overwhelmed. First, you can get results with small changes, so you can pick and choose which healthy changes to make as you are ready.

Second, help is available. Besides contacting your doctor and healthcare team for information and support, you can depend on Lark 24/7 to guide healthy choices, monitor your sleep, activity, and diet, and support you in your quest to lower A1C.