Anion Gap
The anion gap is calculated from sodium, potassium, chloride, and bicarbonate readings on a blood chemistry panel. It estimates the contribution of unmeasured negatively-charged substances (anions) in the blood, like phosphates and proteins.
Why it matters: An elevated anion gap can signal accumulation of acids in the body — for example during ketosis, certain medication exposures, or kidney function changes. A typical gap is one input among several in acid-base reviews.
May increase with:
May decrease with:
What is Anion Gap?
The anion gap is calculated from sodium, potassium, chloride, and bicarbonate readings on a blood chemistry panel. It estimates the contribution of unmeasured negatively-charged substances (anions) in the blood, like phosphates and proteins.
What might a high or low Anion Gap mean?
An elevated anion gap can signal accumulation of acids in the body — for example during ketosis, certain medication exposures, or kidney function changes. A typical gap is one input among several in acid-base reviews.
What is the typical reference range for Anion Gap?
The general-population reference range shown here is 3 – 16 mEq/L. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.
What can affect Anion Gap?
It may be higher with: Metabolic acidosis, Toxin ingestion, Ketoacidosis. It may be lower with: Hypoalbuminemia, Hypercalcemia.
Track your Anion Gap over time
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