High unstable alc-1 generally refers to high unstable glycated hemoglobin, which may be diabetic or caused by high blood sugar. Glycated hemoglobin is a product formed when blood glucose combines with hemoglobin in red blood cells through non-enzymatic action. Glycated hemoglobin formation is irreversible, and its concentration is related to the life span of the red blood cells and the concentration of blood glucose during that period. Glycated hemoglobin can assist in the diagnosis of diabetes mellitus and can reflect the control of blood glucose within the last 3 months. The level of glycated hemoglobin in diabetes depends on the concentration of blood glucose and the time of contact between blood glucose and hemoglobin, and diabetes is a metabolic disease characterized by hyperglycemia, so unstable high glycated hemoglobin can occur. However, the diagnosis of diabetes mellitus mainly refers to the typical symptoms of “three more and one less”, i.e., excessive drinking, excessive eating, excessive urination, weight loss, as well as fasting blood glucose, 2-hour postprandial blood glucose and random blood glucose. It is recommended that patients with high Alc-1 levels should go to the hospital in time and under the guidance of the doctor for further examination to make a clear diagnosis.