Ketones are chemicals that the body creates when it breaks down fat to use for energy. The body does this when it doesn't have enough insulin to use glucose - the body's normal source of energy. When ketones build up in the blood, they make it more acidic. When ketone levels are too high, diabetic ketoacidosis (DKA) can develop. You can "self-measure" your ketones and your Healthcare professional will guide on you how much insulin is needed depending on the result shown.