Ketones Say: kee-tones Glucose (a type of sugar) is the body's main energy source. But when the body can't use glucose for energy, it uses fat instead. When fat is broken down, chemicals called ketones are produced. They get into a person's blood and urine (pee). High levels of ketones cause the blood to become more acidic. This can occur when not enough food has been eaten to provide glucose for energy, or it can occur in diabetes, when the body can't use glucose normally. Back to Articles Related Articles Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.