Body composition
Extracellular water
The water outside your cells: blood plasma, and the fluid in the spaces between tissues.
Unit L
What it is
The water outside your cells: blood plasma, and the fluid in the spaces between tissues.
Why it matters
This is the compartment that swells with fluid retention, inflammation and injury, so it moves for reasons the rest of the sheet does not.
Reading the number
A single value says little, because it scales with body size. The ECW/TBW ratio is where this compartment becomes readable.
What moves it
salt intakehydrationinflammation or injurylong periods standing or sittingmenstrual cycle
When to raise it
Worth mentioning a persistent rise, particularly with visible swelling.
Also known as
On a report in another language.
A lab report names this analyte in its own language. Vitals Vault recognises each of these and files them all under Extracellular water.
ECWÁgua ExtracelularRakuväline vesiExtrazelluläres WasserAgua extracelularEau extracellulaire
Catalog entry last updated 2026-08-29. Browse all 165 metrics.