Low Blood Sodium Levels Can Cause Anxiety by Altering Brain Chemistry in Mice

Recent research has uncovered that chronic hyponatremia, a condition characterized by persistently low sodium levels in the blood, can directly induce anxiety-like behaviors in mice through disruption of brain chemicals. Traditionally viewed as a silent condition, hyponatremia—often caused by illnesses such as liver cirrhosis, heart failure, or syndrome of inappropriate antidiuresis (SIAD)—has now been linked to neurological and psychological effects.

In a study published in Molecular Neurobiology, scientists from Fujita Health University in Japan demonstrated that low blood sodium levels interfere with monoaminergic signaling in the amygdala, a brain region involved in emotion and fear processing. The research team, led by Professor Yoshihisa Sugimura, showed that mice with induced CHN exhibited increased anxiety behaviors in standard behavioral tests, such as the light/dark transition and open field assessments.

Biochemical analysis revealed significant reductions in serotonin and dopamine levels in the amygdala of these mice, along with decreased ERK phosphorylation, a molecular marker related to emotional regulation. These findings suggest that hyponatremia disturbs the delicate balance of mood-regulating neurotransmitters within key brain regions.

The team also found that correcting sodium levels by ceasing desmopressin infusion and switching to a normal diet alleviated anxiety behaviors and normalized neurotransmitter levels. This indicates that the psychological effects of hyponatremia are reversible with proper treatment.

While the study was conducted on mice, implications for humans are clear, especially considering that chronic hyponatremia is common among older adults and individuals with chronic illnesses. Recognizing and managing hyponatremia could mitigate associated neurological and psychological symptoms, potentially improving quality of life.

This research underscores that hyponatremia is not merely a metabolic abnormality but a condition with significant neurological consequences. Early diagnosis and intervention could be crucial in preventing or alleviating anxiety linked to low sodium levels.

Source: https://medicalxpress.com/news/2025-06-sodium-blood-triggers-anxiety-mice.html