Ketonuria

Ketonuria is a medical condition in which abnormally high amounts ketone bodies (a byproduct of the breakdown of cells) are present in the urine.

It is seen in conditions in which the body produces excess ketones as an alternative source of energy. It is seen during starvation or more commonly in type 2 diabetes mellitus. Production of ketone bodies is a normal response to a shortage of glucose, meant to provide an alternate source of fuel from fatty acids. For instance, after 24 hours of fasting the blood will have increased levels of ketone bodies (called ketonemia or ketosis), but all of it will be used by the muscles and very little will remain to be excreted in urine.

Diabetics prone to ketonuria need to monitor their urine for signs of ketone buildup that could lead to life-threatening symptoms unless promptly treated.