Host: What is the A1c lab test?Kathy Reily: The A1c lab test is a blood test that is done usually every three to four months and this is the average blood sugar for the last 60-90 days. So, the lab test takes all of your blood sugar for the last two to three months, averages them together and this lab test is expressed as a percentage which then correlates into a blood sugar. So, for instance, in A1c of 6.5% would translate into a blood sugar of about 150 and the goal for the A1c would be to get that number as close to 6.0 as possible.