Ketoacidosis, a condition that can happen to people with diabetes, occurs when the body uses fat instead of glucose for fuel. 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.
Symptoms of ketoacidosis include nausea, vomiting, belly pain, fast breathing, and, in severe cases, unconsciousness. People with ketoacidosis need to get emergency medical treatment.