What can cause a fruity, sweet smell in urine, suggesting diabetes mellitus or starvation?

A fruity, sweet smell in urine is primarily associated with the presence of ketones. This occurs in conditions such as diabetes mellitus and starvation when the body starts breaking down fats rather than carbohydrates for energy. In diabetes, particularly in poorly controlled cases, the lack of insulin leads to the mobilization of fatty acids, resulting in ketone production. Ketones, including acetone, are volatile compounds, contributing to that characteristic fruity odor.

This sweet smell serves as an important clinical indicator, signaling to healthcare professionals that there may be underlying metabolic disturbances, specifically related to carbohydrate metabolism. Recognizing this symptom can facilitate timely diagnosis and intervention before more severe complications develop.