Plasma osmolality
（重定向自Serum osmolality）
Plasma osmolality measures the body's electrolyte-water balance. There are multiple methods for arriving at this quantity through measurement and calculation.
Osmolality and osmolarity are measures that are technically different, but functionally the same for normal use. Whereas osmolality (with an “ℓ”) is a measure of the osmoles (Osm) of solute per kilogram of solvent (osmol/kg or Osm/kg), osmolarity (with an “r”) is defined as the number of osmoles of solute per liter (L) of solution (osmol/L or Osm/L).