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

Other possible complications involve hyponatremia, in which sodium levels in the blood drop too low, metabolic alkalosis, in which acid levels become unbalanced, and hemolytic uremic syndrome, in which red blood cells and platelets are destroyed. —Don Sweeney april 14, Sacbee.com, 14 Apr. 2026

However, hyponatremia, a condition that results from drinking too much water and effectively diluting the sodium content of your blood, can actually be far more dangerous. —Brad Stulberg, Outside, 26 Mar. 2026

Symptoms of hyponatremia, or having abnormally low sodium levels in the blood, can include seizures, muscle cramping, nausea and vomiting according to the Cleveland Clinic. —Lily Hautau, CNN Money, 21 Mar. 2026

The symptoms and signs of hyponatremia depend on the severity. —Angelica Bottaro, Verywell Health, 20 Jan. 2026

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