# Pseudohyponatremia Caused by Severe Hemolysis

## TL;DR

A 78-year-old man's blood test initially showed low sodium due to severe hemolysis, but further testing revealed it was a false reading.

## Contribution

This case highlights pseudohyponatremia caused by severe hemolysis and clarifies its diagnostic implications.

## Key findings

- Initial blood tests showed decreased serum sodium due to severe hemolysis.
- Repeat testing showed normal sodium levels and no hemolysis.
- Pseudohyponatremia was diagnosed as a result of hemolysis in the initial sample.

## Abstract

A 78-year-old man with influenza presented to the hospital. Initial blood tests revealed severe hemolysis accompanied by a decreased serum sodium concentration. However, repeat testing showed no hemolysis, and the serum sodium level was within the normal range. Notably, the serum sodium concentration in the initial sample, when measured using a blood gas analyzer, was also normal. These findings led to a diagnosis of pseudohyponatremia secondary to severe hemolysis. The underlying mechanisms of this condition are discussed herein.