Ketones in urine are a sign of insulin deficiency or an indication that the body is using fat instead of carbohydrates as a source of energy. Ketones are chemicals formed when the body breaks down fat for energy, as WebMD explains.
Ketones are made when the body does not receive enough carbohydrates through diet or the body is not able to use glucose properly, according to WebMD. In healthy individuals, ketones are made in the liver and are completely metabolized, so only small amounts appear in the urine.
However, when the body gets an insufficient supply of carbohydrates, fat becomes its main source of energy, and it makes large amounts of ketones as a metabolic byproduct. This condition is known as ketoacidosis, according to Healthline.
Having a high concentration of ketones in the urine is called ketonuria. It is caused by health conditions such as diabetes and dietary conditions such as low-carbohydrate diets, prolonged vomiting and starvation. It also occurs during pregnancy.
A urine test is the recommended way to test ketone levels. This can be done in a laboratory or at home using a ketone screening strip. When conducting a ketone test at home, avoid getting any foreign matter, such as toilet paper or pubic hair, in the urine sample, as WebMD advises.
Any detected level of ketone is abnormal for a blood or urine test. Moderate or slightly elevated ketones in women with gestational diabetes could potentially harm the fetus. However, an extremely elevated number of ketones, diabetic ketoacidosis, is potentially fatal, according to WebMD.