Hemoglobin A1C Blood Test: Description & Optimal Ranges

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  • 0:05 Hemoglobin A1C Blood Test
  • 1:04 How It Works
  • 3:26 Ranges
  • 4:22 Lesson Summary
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Lesson Transcript
Instructor: Rebecca Gillaspy

Dr. Gillaspy has taught health science at University of Phoenix and Ashford University and has a degree from Palmer College of Chiropractic.

The hemoglobin A1C blood test is a tool used to measure a person's blood sugar levels over the past few months. Learn about the A1C test and how it can help individuals manage their diabetes and blood sugar related disorders.

Hemoglobin A1C Test

You can tell a fair amount about a person's health by doing a routine physical exam. Findings from this type of exam provide a general overview of a person's state of health, but if you want to fully assess a person's risk of disease, you have to go below the surface. For this information, nothing beats a blood test.

Blood tests are able to pick up on changes going on internally long before they manifest into external signs. For example, if you have concerns about high blood sugar or diabetes, you can get a good assessment of this condition by running a hemoglobin A1C blood test, also referred to as an A1C test, which is a blood test that shows the average blood sugar level over the last few months. In this lesson, you will learn how this test works and how it can help in the management of blood sugar disorders, like diabetes.

How It Works

To build your understanding of hemoglobin A1C, let's go inside a blood vessel. Here we find many substances floating around, but for this lesson, we will focus on just two: red blood cells and glucose.

As you know, red blood cells contain hemoglobin, which is the protein that carries oxygen. You also know that the common name for glucose is blood sugar. If you have children, then you are well aware that sugar is sticky. This stickiness causes glucose molecules to stick to the hemoglobin in your red blood cells. This bonding of a protein and sugar molecule is called glycation. The resulting glycated hemoglobin is referred to as hemoglobin A1C, or simply A1C.

Your red blood cells live for about 90 to 120 days. During their lifespan, they are picking up these sticky glucose molecules and gaining a coating, almost like a sugary candy shell. If your blood sugar level is high, this candy shell will grow thick.

And this is the real value of the hemoglobin A1C blood test. You see, your blood sugar level varies constantly, due to factors like the time of day, your activity level and even hormonal changes. So, when you try to test your blood sugar level using a glucose monitor that pricks your finger, you are only gaining an understanding of the glucose level at that particular moment. With the A1C test, however, you gain an understanding of your blood sugar control over the past 90 to 120 days, which is the lifespan of the red blood cell.

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