Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Hyponatremia laboratory findings
Introduction
Overview
Overview
In hyponatremia, depending on the cause, there can be different laboratory abnormalities.
To see the causes of hyponatremia, click here.
To see the differential diagnosis of hyponatremia, click here.
Laboratory Findings
Laboratory Findings
Biochemical evaluation for finding the etiologies of hyponatremia :
- CT scan for brain chest abdomen and pelvis is necessary for patients to evaluate the causes like SIAD( tumor detection ), and differentiate from other causes with the same presentation.
For different causes of hyponatremia, click here.
For approach to differential diagnosis, click here.
For the clinical approach to diagnosis, click here.
Laboratory findings in different causes of hyponatremia [1]:
| Conditions | Sodium status | Plasma osmolality | Urine osmolality | Differentiation of causes |
|---|---|---|---|---|
| Hypervolemic hyponatremia | TBW ↑↑
Serum Na ↑ |
< 275 mOsm/kg | > 100 mOsm/kg | UNa > 20 mEq/L:
UNa < 20 mEq/L:
|
| Euvolemic hyponatremia | TBW ↑
Serum Na ↔ |
< 275 mOsm/kg | > 100 mOsm/kg | Variable UNa :
UNa > 40 mEq/L:
|
| Hypovolemic hyponatremia | TBW ↔
Serum Na ↓↓ |
< 275 mOsm/kg | > 500 mOsm/kg | UNa > 30 mEq/L:
UNa < 30 mEq/L:
|
References
References
- ↑ Wiebke Fenske, Sebastian K. G. Maier, Anne Blechschmidt, Bruno Allolio & Stefan Stork (2010). “Utility and limitations of the traditional diagnostic approach to hyponatremia: a diagnostic study”. The American journal of medicine. 123 (7): 652–657. doi:10.1016/j.amjmed.2010.01.013. PMID 20609688. Unknown parameter
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Saeedeh Kowsarnia M.D.[2]