The hemoglobin A1C test is an important test to evaluate how effectively you are controlling type 2 diabetes.

Hemoglobin is the protein in your bloodstream that carries oxygen. In the setting of elevated blood glucose levels, hemoglobin binds to glucose. The hemoglobin A1C (glycosylated hemoglobin) blood test measures the amount of hemoglobin that is bound to glucose.

The hemoglobin A1C test determines how well the blood glucose level has been regulated over time. An elevated hemoglobin A1C measurement correlates with poorly controlled diabetes. This test can help monitor a person's response to treatment for diabetes.

Hemoglobin A1C may be performed any time of the day.

Normal Hemoglobin A1C: 2.2% to 4.8%