Sodium Change Calculator
Correct measured serum sodium for hypertriglyceridemia using the pseudohyponatremia correction formula. Free online sodium correction calculator for healthcare professionals.
About This Calculator
The Sodium Change Calculator helps healthcare professionals correct measured serum sodium levels in patients with hypertriglyceridemia. When triglycerides are elevated, lab tests can falsely report low sodium levels — a phenomenon known as pseudohyponatremia. This calculator uses the standard correction formula to estimate the true sodium concentration.
The correction formula is: Corrected Na⁺ = Measured Na⁺ + 0.002 × (Triglycerides − 100). The factor 0.002 represents the decrease in measured sodium (in mEq/L) for each 1 mg/dL increase in triglycerides above the normal baseline of 100 mg/dL. For example, a patient with measured Na of 130 mEq/L and triglycerides of 500 mg/dL would have a corrected Na of 130 + 0.002 × (500 − 100) = 130.8 mEq/L.
This calculator is relevant for all regions — IN, US, and UK. The unit toggle supports both mg/dL (common in India and the US) and mmol/L (common in the UK and Europe). Note that this formula is specific to hypertriglyceridemia; for hyperglycemia-associated pseudohyponatremia, use the Hillier or Katz correction formulas found in the Sodium Correction Calculator.
Regional Notes
- India: Lipoprotein(a) and familial hypertriglyceridemia are common. Standard lipid panels report triglycerides in mg/dL.
- US: The National Lipid Association guidelines recommend screening all adults for lipid disorders. Triglyceride units are mg/dL.
- UK: NICE guidelines recommend mmol/L units. Use the unit toggle to switch between systems. The formula adjusts automatically.
Disclaimer: This tool is for educational reference only. Always verify findings with clinical judgment and consult a licensed healthcare professional for patient management decisions.
Frequently Asked Questions
What is pseudohyponatremia?
Pseudohyponatremia is a false low sodium reading caused by elevated triglycerides or proteins in the blood. The lab test shows low sodium because lipids occupy space in the plasma volume, but the actual sodium concentration in plasma water is normal.
How does the sodium change formula work?
The formula adds 0.002 mEq/L of sodium for every 1 mg/dL of triglycerides above 100 mg/dL. The correction factor accounts for the volume displacement effect of lipids in the plasma. The corrected sodium equals the measured sodium plus 0.002 times (triglycerides minus 100).
What triglyceride level causes pseudohyponatremia?
Significant pseudohyponatremia typically occurs when triglycerides exceed 500 mg/dL (5.65 mmol/L). Mild effects can be seen above 200 mg/dL. For every 500 mg/dL increase in triglycerides, measured sodium decreases by approximately 1 mEq/L.
Is this calculator suitable for clinical use?
This calculator is for educational and reference purposes. Always consult a licensed healthcare provider for actual patient management. The correction formula provides an estimate — true sodium measurement may require direct ion-selective electrode (ISE) methods.
Can I switch between mg/dL and mmol/L?
Yes, the calculator supports both units for triglycerides. You can toggle between mg/dL (commonly used in the US and India) and mmol/L (commonly used in the UK and Europe). The conversion factor is 1 mmol/L = 88.57 mg/dL.
What other conditions cause pseudohyponatremia?
Besides hypertriglyceridemia, pseudohyponatremia can be caused by multiple myeloma, Waldenström macroglobulinemia, IV immunoglobulin infusion, and rarely hypercholesterolemia. High blood glucose requires a different correction formula (Hillier or Katz method).
Who should use this calculator?
This calculator is designed for healthcare professionals including physicians, medical residents, nurses, and medical students who need to correct sodium values in patients with elevated triglycerides. It helps distinguish true hyponatremia from pseudohyponatremia.