Ketone bodies are intermediate metabolites in the oxidative metabolism of fat, including acetoacetic acid, beta-hydroxybutyric acid, and acetone. If β-hydroxybutyric acid is elevated in diabetic patients, it may be related to ketoacidosis, prolonged starvation, etc. Prompt medical attention is recommended. Beta-hydroxybutyric acid can be elevated in diabetic ketoacidosis. Blood ketone bodies can also be elevated by prolonged starvation, vomiting in pregnancy, malnutrition, severe dehydration, acute alcoholism, and after strenuous exercise. In addition, β-hydroxybutyric acid measurement can also be used to understand the fat and protein mobilization in patients with severe injuries, acute and serious illnesses, sepsis, and taking nutritional supportive therapy. If β-hydroxybutyric acid is elevated in diabetic patients, it is recommended to consult a doctor in time to clarify the cause of the disease through professional examination, and then carry out treatment according to the cause of the disease.