The HbA1c (Glycosylated Hemoglobin) test is a blood test used to measure the average blood sugar level over the past two to three months. Hemoglobin is a protein in red blood cells that carries oxygen, and when it is exposed to high levels of sugar in the blood, it becomes glycated, forming HbA1c. The HbA1c test is used to diagnose and monitor diabetes, as it provides a picture of the average blood sugar level over time, rather than just at one moment in time. The test is also used to monitor the effectiveness of diabetes treatment and to identify people who may be at risk of developing diabetes. The HbA1c test is a simple and non-invasive blood test that can be done at any time of the day, without fasting or special preparation. Results are reported as a percentage, with higher percentages indicating higher average blood sugar levels over the past two to three months. The HbA1c test is an important tool for managing diabetes and preventing complications associated with high blood sugar levels, such as heart disease, kidney disease, and nerve damage.