Normal range for serum osmolality is?

• A. 275-295 osm/kg
• B. 200-250 osm/kg
• C. 300-350 osm/kg
• D. 100-150 osm/kg

Answer: (A)

Serum osmolality tells us how concentrated the blood is, mainly determined by sodium, glucose, and urea, and it reflects the body’s water balance. The normal range is about 275 to 295 osm/kg. Values within this window indicate typical hydration status, while far lower or higher values point to hypo- or hyperosmolar states, respectively. The other provided ranges (too low or too high) fall outside this normal window, so they don’t fit as the normal range.