Routine urine ketone bodies (+-), usually not harmful to the body, mainly due to fasting hunger state to check the urine routine. Of course, it is also necessary to exclude the possibility of diabetic ketoacidosis and to perform a blood glucose test. If this is the cause, it may lead to hyperkalemia and severe fluid loss, which may lead to shock if it continues to progress. If the patient checks the urine routine in fasting state, the presence of ketone bodies (+-) is very common, mainly because the patient’s fat metabolism is enhanced in the state of starvation, and the product of fat metabolism is ketone bodies. Ketone bodies are excreted through the urine to show urinary ketone bodies (+-). This condition is not harmful to the body, and urinary ketone bodies turn negative after starvation is relieved. However, if urinary ketone bodies continue to be positive or even increase further, the possibility of diabetic ketoacidosis should be excluded. Diabetic patients with impaired blood glucose application also mobilize fat metabolism and produce more ketone bodies, which can also lead to positive urinary ketone bodies. This is the time to perform a blood glucose test, and once the blood glucose is found to be significantly elevated, prompt treatment should be given to prevent the possibility of hyperkalemia and shock.