This is most common in untreated type 1 diabetes mellitus, when the liver breaks down fat and proteins in response to a perceived need for respiratory substrate. It can also occur with people undergoing hunger strikes, fasting over 3 days, or people starving to death as the body is forced to break down fat for sustenance due to their lack of outside nutrition.
Ketoacidosis can be smelled on a person's breath. This is due to acetone, a direct byproduct of the spontaneous decomposition of acetoacetic acid. It is often described as smelling like fruit or nail polish remover.
Ketoacidosis should not be confused with ketosis, which is one of the body's normal processes for the metabolism of body fat. In ketoacidosis, the body fails to adequately regulate ketone production causing such a severe accumulation of keto acids that the pH of the blood is substantially decreased.
In diabetic patients, ketoacidosis is usually accompanied by insulin deficiency, hyperglycemia, and dehydration. Particularly in type 1 diabetics the lack of insulin in the bloodstream prevents glucose absorption and can cause unchecked ketone body production (through fatty acid production) potentially leading to dangerous glucose and ketone levels in the blood. Hyperglycemia results in glucose overloading the nephron and spilling into the urine. Dehydration results following the osmotic movement of water into urine, exacerbating the acidosis.
In alcoholic ketoacidosis, alcohol causes dehydration and blocks the first step of gluconeogenesis. The body is unable to synthesize enough glucose to meet its needs, thus creating an energy crisis resulting in fatty acid metabolism, and ketone body formation.