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.
Endocrinology Advisor Articles
- ADA Releases Updated Guidelines for Managing Pediatric Type 1 Diabetes
- Relationship Between HbA1c and Coronary Artery Disease
- The Obesity Paradox in Diabetes: Conceptual and Clinical Approaches
- Nonfunctioning Adrenal Incidentaloma Associated With Metabolic Syndrome
- Cost-Benefit Analysis of Insulin Analogs in Type 2 Diabetes
- Self-Administered Contraceptive Vaginal System Approved for Up to 1 Year of Use
- Predictors of Weight Loss in Postpartum Women With Gestational Diabetes
- Genetic Screening May Predict Osteoporosis, Fracture Risk
- DPP-4 Inhibitors and Incidence of Rheumatoid Arthritis in Type 2 Diabetes
- AMA Adopts Policy on Augmented Intelligence