Low Serum or Plasma Sodium
Increase in extracellular fluid volume as produced by congestive heart failure, cirrhosis and ascites, producing dilutional hyponatremia
GI loss of sodium from vomiting, diarrhea, or malabsorption, especially with replacement of fluid and not electrolytes
Renal sodium loss from diuretic use or chronic renal insufficiency
Addison's disease producing adrenal insufficiency
Syndrome of inappropriate antidiuretic hormone secretion (SIADH), as caused by a CNS lesion, pulmonary disease, carcinoma, porphyria
Suggested Additional Lab Testing
Tests for the presence of congestive heart failure and cirrhosis
Indicators of renal function, such as creatinine and BUN
Serum aldosterone level
Serum or plasma BUN, and urine sodium and osmolarity, are valuable in demonstrating hyponatremia and differentiating among the causes of hyponatremia.
In SIADH, both urine sodium and urine osmolarity are increased.
In the presence of a diuretic inducing hyponatremia, urine sodium is increased, but urine osmolarity is usually isotonic to plasma.
Copyright © 2017, 2013 Decision Support in Medicine, LLC. All rights reserved.
No sponsor or advertiser has participated in, approved or paid for the content provided by Decision Support in Medicine LLC. The Licensed Content is the property of and copyrighted by DSM.
Sign Up for Free e-newsletters
Psychiatry Advisor Articles
- Efficacy, Safety of Long-Term Ketamine Administration Still In Question
- Etiology of Schizophrenia: Strong Association With Certain Rare Copy Number Variants
- KCNQ Channel Potentiator Ezogabine Delivers Promising Results in Major Depressive Disorder
- Vulnerability to Psychosocial Disability in Psychosis
- Polygenic Risk Scores May Predict Antipsychotic Efficacy in Schizophrenia
- Cannabis Use, Cannabis Use Disorder Linked to Psychotic, Depressive Symptoms
- Abstinence From Regular Cannabis Use Improves Memory Among Adolescents, Young Adults
- Association Between Opioid and Benzodiazepine Misuse and Suicidal Ideation
- Group Cognitive Behavioral Therapy Is Effective Treatment for Adolescent Anxiety
- The Intersection of Eating and Alcohol Disorders: Detecting and Managing "Drunkorexia"