Understand Your Test


Formal Name
Osmolality (plasma, urine, stool)

Why Get Tested?

To help evaluate the body's water and electrolyte balance; to investigate low sodium levels in the blood (hyponatremia) and increased or decreased urine production; to detect alcohol poisoning due to ingestion of toxins such as methanol or ethylene glycol; to monitor the effectiveness of treatment for conditions affecting osmolality; to help determine the cause of chronic diarrhea.

When To Get Tested?

When someone has a low blood sodium level, is taking mannitol (an osmotic diuretic), may have ingested methanol, ethylene glycol, or isopropyl alcohol, is producing significantly increased or decreased amounts of urine, or has chronic diarrhea.