Definition
What Sodium measures
Sodium is the main electrolyte in the fluid outside cells. The kidneys and thirst hormones keep it in a tight band, so the blood value is really a water-balance gauge.
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Kidney & electrolytesEssentialCompletemmol/L
Sodium
The primary water-balance electrolyte
Illustrative sample band · Synthetic
140mmol/L
134Sample target 137–143 mmol/L146
Why it matters
How clinicians usually read it
Because the body defends sodium so tightly, even small deviations are informative about hydration, hormones, and medications rather than about dietary salt on a given day.
When it reads low
A lower value can mean
A low sodium can follow excess water intake, certain medications, or hormonal conditions. Meaningfully low values cause symptoms and warrant prompt clinical attention.
When it reads high
A higher value can mean
A high sodium usually means a water deficit — not enough fluid intake for the day's losses. Persistent elevation deserves review of fluids and medications.
Questions for a clinician
Bring the number into a real conversation
01
Could my fluid intake or a medication explain this value?
02
Is this stable for me across draws, or a new shift?
03
At what level would you want a repeat or further work-up?
Educational boundary
Educational information only. Displayed ranges are illustrative sample bands, not a diagnosis, treatment plan, or substitute for the contracted laboratory report and a qualified clinician.
See it as a sample result
The sample dashboard shows an illustrative reading, target band, and trend for Sodium.