The normal value of glycosylated hemoglobin is 4-6%, which reflects the average blood glucose level in the past 2-3 months, and is the “gold standard” of diabetes blood glucose control, closely related to diabetes complications. Here we will get to know the ins and outs of glycosylated hemoglobin production. I. What is glycated hemoglobin? Glycated hemoglobin is literally glycated hemoglobin, which is glucose bound to hemoglobin through a chemical reaction. So, we first need to know what is meant by hemoglobin, the main role of hemoglobin is to participate in the transport of oxygen, through breathing, the oxygen in the air into our trachea and lung bubbles, from the alveoli absorbed into the blood, and then brought to various tissues of the body by the blood circulation, and then absorbed and used by the tissues, the red blood cells in the blood vessels are like a container, these oxygen into the container to be transported In order to prevent the oxygen entering the container from running around, some tool is needed to fix it, and this tool is hemoglobin. Therefore, the main function of hemoglobin is to bind and transport oxygen. When hemoglobin encounters glucose in the blood during the process of oxygen transport, it is forced to be firmly tied to it, and from then on, hemoglobin becomes “glycated hemoglobin”. So, how does hemoglobin become glycated hemoglobin when it encounters glucose? Glucose is an important source of energy for the body, and is transported in the bloodstream, where it enters the red blood cells and encounters hemoglobin. Normally, the concentration of glucose in the blood fluctuates in a normal range, with fasting venous plasma glucose of 3.9-6.1 mmol/L and venous plasma glucose <7.8 mmol/L 2 hours after a meal. At this time, very little of the hemoglobin encounters glucose, and only 4-6% of the hemoglobin becomes glycated hemoglobin. However, with diabetes, blood glucose levels are elevated. As the glucose level in the blood rises and over time, the binding of hemoglobin and glucose goes beyond the normal range, causing an increase in glycated hemoglobin. The binding of hemoglobin to glucose is irreversible, so its lifespan is the same as the lifespan of red blood cells, which is about 120 days from birth to death. New red blood cells are constantly being generated and old red blood cells are constantly dying, and in this process of alternation between old and new, glycated hemoglobin is also alternating between old and new, and there is also constant new life and death.