Can Hyponatremia Cause Dizziness?
Yes, hyponatremia can cause dizziness—this is a well-established symptom of mild to moderate hyponatremia and should prompt evaluation of serum sodium levels.
Clinical Presentation of Hyponatremia
Dizziness is a recognized manifestation of hyponatremia across the severity spectrum:
- Mild to moderate hyponatremia (125-134 mEq/L) commonly presents with dizziness, along with headache, muscle cramps, gait instability, lethargy, and confusion 1
- Dizziness is listed among the typical unspecific symptoms of hyponatremia encountered in emergency departments, alongside nausea and falls 2
- Even mild chronic hyponatremia is associated with gait disturbances and increased fall risk—patients with hyponatremia report falls more frequently (23.8% vs 16.4% in normonatremic patients) 3
Symptom Severity Based on Sodium Levels
The severity and type of symptoms depend on both the absolute sodium level and rapidity of onset:
- Mild symptoms (sodium 130-134 mEq/L): nausea, vomiting, weakness, headache, dizziness, and mild neurocognitive deficits 4
- Moderate symptoms (sodium 125-129 mEq/L): more pronounced dizziness, confusion, and gait instability 1
- Severe symptoms (sodium <125 mEq/L): delirium, confusion, impaired consciousness, ataxia, seizures, and potentially coma 4, 1
Chronic hyponatremia (developing over >48 hours) typically causes lethargy, dizziness, weakness, headache, nausea, and confusion, whereas acute hyponatremia (<48 hours) more commonly presents with delirium, seizures, and cerebral edema 5
Important Clinical Pitfall
Do not attribute blurry vision to hyponatremia—while dizziness is a legitimate symptom, blurry vision is not typically caused by hyponatremia and requires investigation for other causes, particularly hyperglycemia in diabetic patients 1. Consider concurrent but unrelated conditions if a patient with hyponatremia reports visual symptoms 1.
Clinical Significance
Hyponatremia affects approximately 5% of adults and 35% of hospitalized patients, making it the most common electrolyte disorder 3. Even mild hyponatremia should not be dismissed, as it is associated with cognitive impairment, increased hospital stays, and mortality 3. The 21% fall risk in hyponatremic patients compared to 5% in normonatremic patients underscores the clinical importance of dizziness as a presenting symptom 6.