Average Blood Sugar
HbA1c, the percentage of hemoglobin in your red blood cells that has sugar attached. Because red cells live about three months, it reflects your average blood sugar over roughly 8-12 weeks.
Why it matters
It is the single most used long-term blood-sugar marker. Trends here show whether your diet, activity, sleep, and medications are keeping glucose steady, long before day-to-day finger-prick readings would.
If it runs high
Higher readings can reflect sustained elevated blood sugar, which over time is associated with prediabetes and type 2 diabetes. Recent illness or certain anemias can also nudge the number.
If it runs low
Lower readings are usually a good sign of steady blood sugar. Unusually low values can occur with some anemias, blood loss, or intensive glucose-lowering treatment, worth reviewing with a clinician.