HbA1C test for laboratory diagnosis of diabetes :It's one of the commonly used tests to diagnose prediabetes and diabetes, and is also the main test to help you and your health care team manage your diabetes.Glycated hemoglobin (HbA1C) is a form of hemoglobin that is chemically linked to a sugar. Most monosaccharides, including glucose, galactose and fructose, spontaneously bind with hemoglobin, when present in the bloodstream of humans. Hemoglobin A1C (HbA1C) test is a blood test that shows what your average blood sugar (glucose) level was over the past two to three months.The hemoglobin A1C (H A1C) test measures the