Ketonemia is most commonly associated with diabetic ketoacidosis. A normal person in a state of hunger will use sugar for energy metabolism to meet the needs of vital organs in the body. When the body’s blood sugar is significantly elevated, accompanied by a lack or insufficient action of insulin, the body cannot effectively use glucose for energy metabolism and can only carry out the oxidative decomposition of fat, and a large amount of ketone bodies will be produced. When the level of ketone bodies in the body increases significantly and exceeds the metabolic capacity of the liver, ketonemia is formed, and ketone bodies are also excreted in the urine. Urine ketone bodies are positive. Diabetic ketonemia is a serious complication of diabetic disease. Clinically, patients need to take insulin to lower blood sugar and give a lot of supplementary sugar-containing fluids to correct ketonemia. Another condition is that ketonemia can also occur in a state of starvation, but in this case the patient’s blood glucose is normal and the ketone bodies are positive, compared to ketoacidosis which is not very serious.