Urine indicates the health levels in our bodies because much of the waste and residue from the body exits through it. Thus, it can contain traces of materials characteristic of both good and bad health.
That being said, a bad odor isn’t usually a strong indicator of a serious problem. For instance, a bad odor could be due to having eaten asparagus recently, or it could also just be another indicator of dehydration. A sweet odor could however, be a sign of diabetes and a foul odor could be a signal of an infection or other potential issues.