HbA1c levels do not fluctuate quickly because once red blood cells are glycosylated, they remain that way until they die (up to 3 months). For this reason, HbA1c levels give a picture of blood glucose control over a long period of time. HbA1c is also the only proven indicator of a person’s risk of developing complications such as stroke, heart attack, nerve damage or damage to small blood vessels in the kidneys and eyes. Blood glucose level tests, on the other hand, cannot give this type of information. As a person’s blood glucose level can be significantly (and immediately) influenced by various factors, including activity, food intake and stress levels, it can fluctuate many times during the day. Consequently, blood glucose levels are a picture of a moment in time and cannot be relied upon to accurately give information to reflect a person’s long-term diabetes management.