Final answer:
A urine dip for ketones can detect the presence of key ketone bodies, including acetone, which appears in larger amounts in the urine when the body metabolizes fat instead of glucose for energy, commonly seen in diabetic conditions.
Step-by-step explanation:
A urine dip for ketones can only detect the presence of ketone bodies, which includes acetone, acetoacetic acid, and ß-hydroxybutyric acid. However, it is typically acetone that is present in the highest amount in urine because it is not utilized by the body and acetoacetic acid converts to acetone on exposure to air. These ketone bodies are by-products of fat metabolism and can indicate that the body is using fat as an energy source rather than glucose. This can occur in conditions such as diabetes mellitus, where there is insufficient insulin or insulin resistance, leading to high glucose levels in the blood, but an inability of the cells to take it in for use as energy. As a result, the body resorts to fat breakdown, which produces an excess of ketones that appear in the urine.
Normal levels of ketone bodies in human blood are less than 1 mg/dl, and healthy individuals typically excrete less than 1 gm/day of ketones in the urine. The presence of higher amounts of ketones in the urine, known as ketonuria, can be indicative of pathological states like uncontrolled diabetes mellitus. In such cases, the acetone level rises, and its odor can sometimes be noted on the breath. Rothera's test, a urine test, is one method used to identify and estimate the concentration of ketone bodies.