For years, physicians and patients have trusted the A1C lab test to judge if a patient's diabetes is well-controlled or not; diabetes physicians and diabetes organizations have urged people with diabetes to get their number under 7 (or in some cases, even lower). A1C, also called hemoglobin A1c, and sometimes abbreviated HbA1c, measures the amount of glucose that's hooked to hemoglobin in red blood cells, and gives an estimate of how the blood glucose has been doing the past 2 to 3 months.

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