Corrected Sodium (Hyperglycemia)
Estimate corrected sodium when serum glucose is elevated.
Last reviewed: February 26, 2026
Clinical disclaimer
Use glucose from the same lab draw as sodium.
Many protocols use 1.6; some use 2.4 for severe hyperglycemia.
How it works
Hyperglycemia lowers measured sodium by shifting water into the extracellular space. Corrected sodium estimates the sodium after accounting for this dilution.
- Corrected Na = measured Na + factor x ((glucose - 100) / 100).
- The calculator supports 1.6 or 2.4 mEq/L per 100 mg/dL above 100.
- Glucose can be entered in mg/dL or mmol/L (converted internally).
Interpretation & caveats
Corrected sodium helps characterize true tonicity in DKA or other hyperglycemic states. Use it alongside clinical status, ketones, and acid-base data.
- Document the correction factor used (1.6 vs 2.4).
- Trends matter more than single values; re-check sodium and glucose during treatment.
- Effective osmolality is calculated from measured sodium and glucose to estimate tonicity.
Rapid bedside workflow
- Confirm measured sodium and glucose units, then verify sample timing relative to treatment changes.
- Calculate corrected sodium with documented factor (1.6 or 2.4) using local protocol preference.
- Interpret corrected sodium alongside effective osmolality, neurologic status, and acid-base context.
- Set fluid strategy and monitoring interval based on trend direction rather than one isolated value.
- Recalculate after meaningful glucose/fluid shifts and document whether trajectory matches expectations.
Reassessment cadence
- Early active treatment: repeat sodium/glucose per protocol in the same treatment block to confirm direction.
- Improving stable trajectory: continue serial labs at protocol cadence with explicit trend documentation.
- Unexpected neurologic change or rapid laboratory movement: immediate repeat labs and escalation.
Escalation triggers
- Worsening neurologic findings, seizure activity, or signs concerning for cerebral edema.
- Corrected sodium trend inconsistent with expected glucose-response trajectory.
- Large sodium or osmolality shifts after therapy adjustments.
- Uncertain correction-factor selection in a high-risk clinical context.
Shift handoff checklist
- Measured sodium/glucose, units, and correction factor used.
- Corrected sodium and effective osmolality with timestamp.
- Current fluid strategy and rationale tied to trend interpretation.
- Next lab timing and explicit escalation threshold for overnight coverage.
Related calculators
References
- Katz MA. Hyperglycemia‑induced hyponatremia—calculation of expected serum sodium depression. N Engl J Med. 1973.
- Hillier TA et al. Hyponatremia: evaluating the correction factor for hyperglycemia. Am J Med. 1999.
Frequently asked questions
High serum glucose draws water out of cells into the extracellular space, diluting measured sodium. Correcting sodium estimates the value after accounting for this water shift.
Many protocols use 1.6 mEq/L per 100 mg/dL glucose above 100. Some use 2.4 in severe hyperglycemia. Follow your local DKA/HHS protocol and document the factor used.
If glucose is 100 mg/dL (5.6 mmol/L) or lower, no correction is applied in this calculator.
Effective osmolality (tonicity) is estimated as 2 x measured Na + glucose/18 (with glucose in mg/dL). It reflects the osmotic effect of sodium and glucose.
Document measured values, units, correction factor, corrected sodium result, and planned recheck timing. This keeps serial interpretation consistent across shifts and reduces treatment drift.