When the body does not have enough insulin or has impaired utilization, the body breaks down fat, which produces acetone, acetoacetic acid and beta hydroxybutyric acid, all three of which are collectively called ketone bodies. When ketone bodies accumulate in the blood to a certain level, they can cause life-threatening complications, which are called diabetic ketoacidosis. Commonly seen in patients with type 1 diabetes, diabetic ketoacidosis is likely to occur when insulin doses are inadequate or treatment is interrupted. Monitoring blood ketones has important clinical significance for the diagnosis and prognosis and treatment of diabetic ketoacidosis. There is another clinical condition that can cause an increase in blood ketone bodies, called starvation ketosis. As a result of long-term starvation, the patient does not have sufficient glucose catabolic function, thus accelerating the body fat decomposition and producing ketone bodies, called starvation hemoketosis.