What is Ketosis?
Ketosis is the presence in the blood of abnormally high levels of acidic substances called ketones. Ketones (also called "ketone bodies") are chemicals with a carbonyl unit (a carbon doubly bonded to an oxygen) that has two alkyl or aromatic (hydrocarbon) substituents bonded to the carbon atom. They include acetoacetic acid, 3-hydroxybutyric acid, and acetone.
What Causes Ketosis?
Ketosis is caused when the body metabolizes body fat for energy purposes, instead of the usual glucose-from-carbohydrates. The ketones are actually produced by the liver from fatty acids, Gluconeogenesis, which result from the breakdown of body fat. As stated, the body doesn't usually metabolize fat for energy: it usually burns glucose which it obtains from carbohydrates. But if there isn’t enough glucose in the bloodstream, (or, in the case of diabetics, if the glucose can't be utilized), the body draws on its alternate energy system, fat stores, for fuel, which causes the appearance of ketones in the blood.
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What is Ketoacidosis?
Ketoacidosis is a dangerous condition for diabetics, the main element being acid, not ketones themselves. In ketoacidosis, the blood pH level becomes dangerously acidic due to an extremely high blood glucose level triggered either because the diabetic patient has no insulin, or else because he/she doesn't respond to insulin. As the diabetic's blood sugar rises, ketones are produced by the body to provide the fuel necessary for life, since the cells can't use the sugar due to the diabetes.
Twin Factors of Ketoacidosis
To recap, in ketoacidosis, it is twin factors of (1) high blood sugar, and (2) high acidity of the blood that trigger the condition, rather than the ketosis itself. The ketones just happen to be an associated element, and are a result of the condition, not the cause.