Diabetes is a common disease caused by the interaction of genetic and environmental factors. The main clinical sign is high blood sugar. Common symptoms include polydipsia, polyuria, polyphagia, and weight loss. Diabetes can cause damage to multiple systems in the body, leading to absolute or relative insulin deficiency and reduced insulin sensitivity of target tissue cells, causing a series of metabolic disorders such as protein, fat, water, and electrolytes. Significant increase in blood sugar can cause acute complications such as diabetic ketoacidosis and hyperosmolar coma. Long-term illness can also cause vascular and neuropathy, resulting in damage to multiple organs and tissues such as the heart, brain, kidneys, eyes, nerves, and skin, affecting the patient's quality of life and even shortening life expectancy. Active prevention and treatment should be carried out.