Table of Contents


What is hypernatremia?

Hypernatremia is the medical term for when the water content of body fluids is deficient compared to sodium; i.e. there is a high sodium ion level in the blood.

Hypernatremia can be the result of sodium excess but is generally associated with dehydration. Patients who develop hypernatremia tend to be elderly or already hospitalized for unrelated reasons.

What are the symptoms of hypernatremia?

Symptoms in adults include:

  • Confusion
  • Muscle spasms
  • Muscle weakness
  • Restlessness
  • Nausea
  • Brain shrinkage, in severe cases

Symptoms in infants include:

  • Tachypnea
  • Muscle weakness
  • Restlessness
  • High-pitched cry
  • Insomnia
  • Lethargy
  • Coma
  • Seizures

What causes hypernatremia?

Hypernatremia is caused by impaired thirst and/or limited access to water, often worsened  by pathologic conditions with increased fluid loss.

Common causes of water loss include:

  • Inadequate intake of water; i.e. unable to ingest water as thirst dictates
  • Excessive losses of water from the urinary tract, which may be caused by glycosuria or other osmotic diuretics
  • Extreme sweating
  • Severe watery diarrhea
  • Excessive water excretion from the kidneys
  • Salt poisoning

How is hypernatremia diagnosed?

Ways to diagnose hypernatremia include:

  • Measuring serum sodium
  • Urine volume assessment
  • Blood osmolality test
  • Water deprivation test

What are the treatments for hypernatremia?

The most common way to treat hypernatremia is rehydration – including oral and IV hydration. However, hydration often involves special solutions (with appropriate levels of sodium) to avoid swelling and cerebral edema.

Where can I find out more about hypernatremia?

Hypernatremia Articles