Ketone bodies (ketones, KET)
Ketone bodies are metabolic end-products produced in the liver. They are acetone, acetoacetic acid and beta-hydroxybutyric acid.
Ketone bodies are generally not found in the urine of healthy individuals, although small amounts of ketones are expelled from the body during urination throughout the day. Such concentrations cannot be detected by regular laboratory methods, so it is generally assumed that there are no ketone bodies in the urine of a healthy individual.
Ketones are found in the urine in disorders of carbohydrate and fatty acid metabolism causing high levels of ketone bodies in the blood (ketonemia).
A medical condition in which ketone bodies are present in the urine is called ketonuria.
Under normal conditions, the body’s energy supply comes from glucose. Glucose accumulates in the body as glycogen. Above all, it accumulates in the liver. Glycogen forms a kind of energy storage which can be quickly mobilized if needed to compensate for a shortage of glucose. In response to a shortage of glucose, glycogen is converted by enzymes into glucose that gets into the bloodstream.
As a result of physical exercise and emotional tension, diseases causing a high body temperature and other factors causing excessive energy expenditure, the stores of glycogen run out and the body starts to use its fat as a source of energy. Ketones are created when the body breaks down fats and then they are expelled during urination.
Unlike adults, children have less glycogen stored and the body switches to fat as a source of energy sooner. As a result, their urinalysis shows ketonuria. High levels of ketone bodies in the urine of newborn babies are almost always due to malnutrition.
If a urinalysis shows ketone bodies and glycose, the patient most likely has diabetes.
Also, ketones may be found in the urine due to dehydration, long fasts, fever, long gastrointestinal disturbance (vomiting or diarrhea).
Ketones in urine during pregnancy (acetone in urine during pregnancy)
Ketonuria may be caused by early toxicosis during pregnancy. Ketones poison the body with acetone affecting the embryo, so ketonuria needs to be treated.