Hyponatremia is a potentially serious condition in which the level of sodium in the blood is too low. An imbalance is created when there is too little sodium for the amount of water in the body. As a result, water moves into the body’s cells causing them to swell.
There are different types of hyponatremia, each resulting in low sodium in the blood:
Hyponatremia may be caused by:
Hyponatremia is more common in older adults. Other factors that may increase your chance of hyponatremia include:
People with mild hyponatremia usually don't have symptoms. As hyponatremia progresses, symptoms will appear and worsen.
Moderate to severe hyponatremia may cause:
You will be asked about your symptoms and medical history. A physical exam will be done. You will be asked about your fluid intake.
Tests may include:
Other tests may be done to look for any underlying causes of your hyponatremia.
Treatment may depend on:
In cases when the sodium has been low for more than 1-2 days, the doctor will want to correct the sodium level slowly. Serious complications may occur when sodium levels rise too rapidly. It can be corrected more quickly if it has been low for a short time.
Treatment options may include:
To help reduce your chance of hyponatremia:
American Society for Nutrition
National Institute of Diabetes and Digestive and Kidney Diseases
The College of Family Physicians of Canada
Elhassan EA, Schrier RW. Hyponatremia: Diagnosis, complications, and management including V2 receptor antagonists (vaptans). Curr Opin Nephrol Hypertens. 2011;20(2):161-168.
Hyponatremia. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T113706/Hyponatremia. Updated January 20, 2016. Accessed December 18, 2017.
Mittal R, Sheftel H, et al. Management of hyponatraemia. Br J Hosp Med (Lond). 2011;72(2):M22-5.
Syndrome of inappropriate antidiuresis (SIAD). EBSCO DynaMed website. Available at: http://www.dynamed.com/topics/dmp~AN~T115360/Syndrome-of-inappropriate-antidiuresis-SIAD. Updated August 4, 2016. Accessed December 18, 2017.
Last reviewed December 2017 by EBSCO Medical Review Board Michael Woods, MD, FAAP
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.