What characteristic of urine may indicate dehydration?

A dark yellow color of urine can indicate dehydration because it signifies a higher concentration of waste products in the urine due to reduced fluid intake. When the body is dehydrated, it preserves water by concentrating the urine, resulting in a darker shade. This darker appearance is a direct indicator that the kidneys are conserving water, which is a physiological response to maintain hydration levels in the body.

In contrast, clear urine typically indicates proper hydration and a well-functioning filtration system in the kidneys. Light yellow urine is also a sign of adequate hydration but not as concentrated as dark yellow. Normal-colored urine falls within a range that can vary based on hydration levels but does not specifically point to dehydration. Thus, the dark yellow color effectively serves as a practical marker showing that a person may need to increase fluid intake to avoid dehydration.