(Dilutional Hyponatremia; Euvolemic Hyponatremia; Hypervolemic Hyponatremia; Hypovolemic Hyponatremia)
- Euvolemic hyponatremia—water level increases, but sodium level stays the same
- Hypervolemic hyponatremia—water and sodium levels increase, but the water gain is greater
- Hypovolemic hyponatremia—water and sodium levels decrease, but the sodium loss is greater
- Syndrome of inappropriate antidiuretic hormone secretion (SIADH)—Antidiuretic hormone signals the kidneys to absorb more water, reducing urine output. In SIADH, the mechanism that stops antidiuretic hormone from collecting water is impaired. This impairment results in excess water in the body.
- Sweating—In people with cystic fibrosis , excess sodium is excreted through sweat. It may also occur in people with severe burns when electrolytes and fluids are not replaced.
- Some diuretics—Increase sodium is lost in the urine.
|Normal Anatomy of the Kidney|
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- Advanced age
Excess water intake without electrolytes—may occur when:
- People are participating in endurance exercise
- There is a lot of vomiting and/or diarrhea
- Certain medications, such as some diuretics or antipsychotics
- Certain health conditions, such as:
- Having prostate surgery
- Sweating in people without cystic fibrosis or severe burns
- Loss of appetite
- Muscle twitching
- Blood tests—to check the sodium level in your blood, and the functioning of your organs
- Urine test—to check the sodium level in your urine
- What is causing the low sodium level
- How long the sodium level has been low
- How low the sodium level is
- Your level of hydration
- Restricting fluid intake
- Identifying the underlying cause and getting proper treatment
- Medications to help remove extra fluid from your body
- IV fluids to deliver sodium restore proper balance
- If participating in sports, drink only as much water as you need to quench your thirst. Sport drinks that provide electrolytes, such as sodium, along with water may be helpful during endurance events.
- Work with your doctor to effectively manage any conditions that you may have.
American Society for Nutriton http://www.nutrition.org
National Institute of Diabetes and Digestive and Kidney Diseases http://www.niddk.nih.gov
Health Canada http://www.hc-sc.gc.ca
The College of Family Physicians of Canada http://www.cfpc.ca
Almond CS, Shin AY, et al. Hyponatremia among runners in the Boston Marathon. N Engl J Med. 2005;352(15):1550-1556.
Ayus JC, Arieff AI. Glycine-induced hypo-osmolar hyponatremia. Arch Intern Med. 1997;157(2):223-226.
Elhassan EA, Schrier RW. Hyponatremia: Diagnosis, complications, and management including V2 receptor antagonists. Curr Opin Nephrol Hypertens. 2011;20(2):161-168.
Hyponatremia. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated July 9, 2014. Accessed November 6, 2014.
Mittal R, Sheftel H, et al. Management of hyponatraemia. Br J Hosp Med (Lond). 2011;72(2):M22-5.
Peng K. Management of hyponatremia. Am Fam Physician. 2004;69(10):2387-2394.
Syndrome of inappropriate antidiuretic hormone secretion (SIADH). EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated December 15, 2012. Accessed November 15, 2013.
- Reviewer: Michael Woods, MD
- Review Date: 12/2014 -
- Update Date: 12/20/2014 -