Sodium Correction Calculator

This sodium correction calculator fixes the results of serum sodium (Na⁺) measurements that can be a little distorted in states of hyperglycemia. The values needed for the estimation are the patient's serum sodium and blood glucose.

Read on to learn how to calculate corrected sodium and to understand the formula for sodium correction.

If you find this calculator useful, check out our other sodium-related tools: fractional excretion of sodium (FENa) calculator, free water deficit calculator, and anion gap calculator.

In the state of hyperglycemia – high blood sugar concentration – water moves from the intracellular to the extracellular space to dilute the excess glucose. This shift can cause a relative decrease in serum sodium levels.

Here are the steps to calculate the corrected sodium level:

1. Insert the patient's serum sodium level (Na⁺). If the test results are in mmol/L, they are equal to the values in mEq/L.

2. Type in the blood glucose level in the preferred unit. You can change it by clicking on the unit symbol. You can also use our glucose unit converter.

3. The calculated corrected sodium is presented in the last field.

4. If you'd like to see the result when using an older version of the equation, click on the advanced mode button.

If you plan to correct the patient's hypo- or hypernatremia, use our sodium correction rate calculator.

The equation was developed by Dr. Teresa A. Hillier and described in the article Hyponatremia: evaluating the correction factor for hyperglycemia in 1998.

corrected sodium level = serum Na⁺ + 0.024 × (serum glucose - 100)

In the advanced mode of the calculator, you can find an older version of the corrected sodium formula. It is an equation developed in 1973 by Dr. Murray A. Katz – Hyperglycemia-Induced Hyponatremia — Calculation of Expected Serum Sodium Depression.

corrected sodium level = serum Na⁺ + 0.016 × (serum glucose - 100)

To correct the sodium levels for hyperglycemia, follow these easy steps:

1. Find your measured sodium levels in milliequivalents per liter.
2. Find your blood glucose (in milligrams per deciliter).
3. Find the corrected sodium levels:
   corrected sodium level = serum Na⁺ + 0.024 × (blood glucose - 100)

Note that the correction goes in both directions and allows us also to consider hypoglycemia.

Hyperglycemia affects the sodium levels in your blood because it forces water outside of your cells. This causes an effective dilution of the electrolytes in your blood, and among them, the sodium. The sodium values measured from your blood must take into account this dilution to tune dosages and treatments properly.

The corrected sodium levels are 137.6 mEq/L. As you can see, they are slightly higher than the measured ones. To find this result, simply apply the formula for the glucose correction of the sodium levels:

corrected sodium level = serum Na⁺ + 0.024 × (blood glucose - 100)

corrected sodium level = 135 mEq/L + 0.024 × (210 - 100) = 137.6 mEq/L.

Diabetes can affect your sodium levels. Be sure to consider your blood glucose levels to adjust the measured sodium to the real value. Hyperglycemia and hypoglycemia affect your electrolyte levels: the measured sodium is overestimated with low blood sugar and underestimated for high levels of blood glucose. Potassium, on the other hand, behaves the opposite way!