Hemoglobin is the chemical that carries oxygen in our red blood cells. However, what you're talking about is a test to measure overall blood Glucose level in the blood for the past 90 days.
The glycosylated hemoglobin or hA1c is it's commonly known gives a good indicator of the average blood sugar level over those past three months.
Ideally, you want your average to stay as close to "normal" as possible, which would be between 120 mg/dl to 150 (the reading you get on your meter). Translated to A1c values, 120 is about 6% and 150 is about 7%.
Too high BG levels wreak all manner of bodily havoc and keeping the A1c at or below 7 has proved to minimize long term BG related problems.
