hyponatremia

noun

hy·​po·​na·​tre·​mia ˌhī-pō-nā-ˈtrē-mē-ə 

variants or chiefly British hyponatraemia

medical

: the condition of having an abnormally low level of sodium in the blood that is typically marked by nausea, vomiting, headache, confusion, fatigue, and muscle cramps and that when severe may be life-threatening if untreated

… aspirin and other pain relievers like ibuprofen … seem to increase the risk for hyponatremia.

—Harvard Health Letter

Hyponatremia, or having low sodium, can cause seizures, coma and even death if untreated.

—Lisa Sanders

Research showed that hydrating too much over the long haul—during a marathon, say, or a long-distance bike ride—dilutes the blood's salt content and can lead to hyponatremia.

—Jeffrey Kluger

hyponatremic

ˌhī-pō-nā-ˈtrē-ik 

adjective

or chiefly British hyponatraemic

hyponatremic encephalopathy

hyponatremic athletes

Examples of hyponatremia in a Sentence

Recent Examples on the Web

If left untreated, polydipsia may lead to the development of hyponatremia or water intoxication. —Danielle Weiss, Verywell Health, 25 Apr. 2025

This can lead to a dangerous electrolyte imbalance called hyponatremia, which causes cells to swell. —Jake Parks, Discover Magazine, 5 Apr. 2025

In extreme cases, consuming a large volume of water without sufficient electrolytes can lead to dangerously low levels of sodium in the blood, a potentially life-threatening condition known as hyponatremia. —Outside Online, 23 Mar. 2025

This can eventually make those cells swell like raisins soaking in water, a potentially dangerous condition called hyponatremia. —Celia Ford, Vox, 7 Dec. 2018

Word History

Etymology

hypo- + New Latin natrium "sodium" + -emia — more at natriuresis

First Known Use

1935, in the meaning defined above

Rhymes for hyponatremia

• academia
• acidemia
• azotemia
• bacteremia
• hyperaemia
• hyperemia
• hypoxemia
• septicaemia
• septicemia
• thalassaemia
• thalassemia
• tularemia

Medical Definition

hyponatremia

noun

hy·​po·​na·​tre·​mia

variants or chiefly British hyponatraemia

-nā-ˈtrē-mē-ə 

: the condition of having an abnormally low level of sodium in the blood that is typically marked by nausea, vomiting, headache, confusion, fatigue, and muscle cramps and that when severe may be life-threatening if untreated

… aspirin and other pain relievers like ibuprofen … seem to increase the risk for hyponatremia.

—Harvard Health Letter

hyponatremic adjective

or chiefly British hyponatraemic

-mik