How this calculator works
The original 1976 publication expresses a percentage increase using triglycerides in g/dL. This page preserves that equation rather than a later differently transcribed formula. It is a historical approximation for analytical interference, not a treatment correction or a prediction of how sodium changes during therapy. Modern direct ion-selective electrode measurements are not subject to the same dilution artefact. The result is an estimate for information only and is not medical advice.
Formula
Increase (%) = 2.1 x triglycerides(g/dL) - 0.6. Estimated sodium = measured sodium x [1 + increase/100]. Convert mg/dL to g/dL by dividing by 1000.
Worked example
At triglycerides 2000 mg/dL, the increase is 2.1 x 2 - 0.6 = 3.6%. Measured sodium 130 mmol/L gives an estimated 134.68 mmol/L, a difference of 4.68.
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Frequently asked questions
Is this a sodium treatment target?
No. It estimates possible measurement bias. Treating an apparent low value without confirming tonicity and method can be inappropriate.
Can I use triglycerides in mmol/L?
This page requires mg/dL. The original equation used mass concentration, and no unverified lipid conversion constant is introduced.
What should confirm a suspected artefact?
The laboratory can identify its measurement method and obtain an appropriate direct measurement. Clinical assessment also considers glucose, proteins and measured osmolality.