The A1C test measures a person's average level of blood glucose during the prior 2-3 months. Hemoglobin is the part of the red blood cell that carries oxygen to the cells and also combines with glucose in the bloodstream. Also called hemoglobin A1c or glycosylated hemoglobin, the test measures the quantity of glucose attached to the red blood cells which is proportional to the quantity of glucose in the blood. More information available at: http://www.diabetes.org/diabetes-basics/common-terms/#sthash.bIAIhlZA.dpuf