Increased osmolality indicates what condition about hydration status?

Increased osmolality typically indicates dehydration. This occurs when there is a relative deficiency of water in the body compared to solutes, which causes an increase in the concentration of solutes in the blood. When the body loses water through various means—like sweating, vomiting, diarrhea, or inadequate fluid intake—the osmolality of the plasma rises, reflecting a more concentrated state.

In dehydrated conditions, your body conserves water by retaining it through mechanisms influenced by hormones such as vasopressin (ADH) that help to concentrate urine. This is a biological response to aid in maintaining homeostasis and prevent further dehydration.

In contrast, fluid retention would lower osmolality as excess fluid dilutes the plasma. Optimal hydration indicates a balance where osmolality remains within a normal range, while overhydration would lower the osmolality even further. Therefore, an increase in osmolality is a clear indicator of dehydration, showcasing a disruption in fluid balance in the body.