A weakly positive urine ketone body indicates the presence of ketone bodies in the urine. Ketone bodies in the urine are intermediate products of fat metabolism, and under normal circumstances, it is produced very rarely. Routine laboratory tests do not detect ketone bodies, so urine ketone bodies should be negative in the urine routine. If it is weakly positive, the most common is the fasting state. In general, if the urine test is done in a fasting state or if there is prolonged starvation, the ketone bodies will appear positive, called starvation ketone bodies. When there is disease, such as repeated vomiting or diarrhea, can cause ketone bodies to rise, appearing weakly positive. Patients who are malnourished and those who have lost weight over a long period of time can have weak positive urinary ketone bodies. The most common disease state is ketoacidosis in diabetes. If the blood sugar is not well controlled, a large amount of ketone bodies will be produced in the urine, and the ketone bodies cannot be utilized, and a positive urine ketone body will occur.