An A1C level that is 6.5 percent or higher on two separate blood tests indicates that a patient has diabetes, according to Mayo Clinic. Someone who has an A1C level of 5.7 to 6.4 percent has prediabetes. A patient with a normal blood sugar should expect a result that is greater than 4.5 percent but still falls below diabetic levels.Continue Reading
A1C levels coordinate with estimated blood sugar levels, explains Mayo Clinic. Someone with long-term uncontrolled diabetes, for example, may have an A1C level of 8 percent, which corresponds to an average blood sugar level of 183 milligrams per deciliter. Meanwhile, a patient with an A1C level of 5 percent has an average blood sugar level of 97 milligrams per deciliter.
After a doctor diagnoses someone with diabetes, he may use regular A1C blood tests to determine how well the patient manages his blood sugar, states Mayo Clinic. In most cases, an A1C level of less than 7 percent is the target number, but a doctor may choose to raise the target depending on the patient.
People who have recently had a blood transfusion or who have heavy or chronic bleeding may have inaccurately low A1C levels, notes Mayo Clinic. Conversely, someone with high levels of iron in his blood may have inaccurately high A1C levels. African-Americans and people with Mediterranean or Southeast Asian heritage may have a hemoglobin variant that gives them either inaccurately high or low A1C levels.Learn more about Medical Ranges & Levels