Sodium Correction Calculator
Calculate corrected sodium levels for hyperglycemia using clinically validated formulas
Calculate Corrected Sodium
Normal range: 135-145 mEq/L (135-145 mmol/L)
Normal fasting: 70-99 mg/dL (3.9-5.5 mmol/L)
Example Calculation
Diabetic Patient with Hyperglycemia
Measured Sodium: 135 mEq/L (appears low)
Blood Glucose: 210 mg/dL (elevated)
Clinical Question: Is this true hyponatremia?
Step-by-Step Calculation (Hillier Formula)
Step 1: Corrected Na = Measured Na + 0.024 × (Glucose - 100)
Step 2: Corrected Na = 135 + 0.024 × (210 - 100)
Step 3: Corrected Na = 135 + 0.024 × 110 = 135 + 2.64
Result: Corrected Na = 137.6 mEq/L (Normal range!)
Normal Laboratory Values
Serum Sodium
135-145 mEq/L
(135-145 mmol/L)
Fasting Glucose
70-99 mg/dL
(3.9-5.5 mmol/L)
Random Glucose
<140 mg/dL
(<7.8 mmol/L)
Diabetic Range
≥126 mg/dL fasting
(≥7.0 mmol/L)
Formula Comparison
Hillier Formula (2024)
Na⁺ + 0.024 × (Glucose - 100)
- • More recent research
- • Higher correction factor
- • Recommended for clinical use
Katz Formula (1973)
Na⁺ + 0.016 × (Glucose - 100)
- • Historical formula
- • Lower correction factor
- • Still used in some centers
Understanding Hyperglycemia's Effect on Sodium Levels
Why Does Hyperglycemia Affect Sodium?
In hyperglycemia, elevated blood glucose creates an osmotic gradient that draws water from intracellular spaces into the extracellular compartment. This water shift dilutes the sodium concentration in the blood, creating a relative decrease in measured serum sodium levels.
Clinical Significance
- •Prevents overtreatment of apparent hyponatremia
- •Guides appropriate fluid and electrolyte management
- •Essential for diabetic emergencies (DKA, HHS)
- •Helps identify true electrolyte disorders
Formula Development
Hillier Formula (2024)
Based on comprehensive analysis of hyperglycemia cases, this newer formula provides more accurate correction for the osmotic effect of glucose.
Corrected Na⁺ = Measured Na⁺ + 0.024 × (Glucose - 100)
Katz Formula (1973)
The original formula developed by Dr. Murray Katz, historically used but may underestimate the correction needed in severe hyperglycemia.
Corrected Na⁺ = Measured Na⁺ + 0.016 × (Glucose - 100)