Hemoglobin A1C Test

Hemoglobin is a protein found in red blood cells. The sugar in your body is called glucose. When glucose builds up in your blood it binds to the hemoglobin in your red blood cells. The A1c test measures how much glucose is bound to the hemoglobin. Since red blood cells live about 3 months, the test measures the average level of glucose in your blood for the past 3 months. If your glucose levels are high, your hemoglobin A1c test will be higher as well.

People who have diabetes need this test regularly to see if their levels are staying within range. The A1C test can also identify prediabetes and diagnose diabetes.