The Hemoglobin A1C test measures the average blood sugar levels over the past two to three months. It assesses the percentage of hemoglobin, a protein in red blood cells, that is coated with sugar. This test is crucial for diagnosing and monitoring diabetes and helps healthcare providers understand how well blood sugar levels are being managed. A normal A1C level is typically below 5.7%. Levels between 5.7% and 6.4% indicate prediabetes, while 6.5% or higher suggests diabetes. Regular testing can help prevent complications associated with high blood sugar, such as heart disease and kidney damage.