Review of Hyponatremia by Helbert Rondon, MD, Published in International Urology and Nephrology

September 18, 2020

Helbert Rondon-Berrios, MD, is a nephrologist specializing in electrolyte disorders at UPMC. In August 2020, he was awarded an NIDDK R21 grant to study the role of oral urea in the treatment of chronic hyponatremia. 

Read Dr. Rondon’s comprehensive review of hyponatremia in International Urology and Nephrology. 

Study Abstract

Defined as a serum sodium concentration of less than 135 mEq/L, hyponatremia is the most common electrolyte disorder, seen in 20 to 35 percent of hospitalized patients. The incidence rate is especially high among ICU patients, post-operative patients, and older patients with associated comorbidities. 

If their hyponatremia is mild to moderate, a patient may present with minimal to no symptoms. 

For patients with a more severe or rapid-onset disturbance, symptoms may include: 

  • Anorexia 
  • Nausea
  • Vomiting 
  • Fatigue 
  • Headache
  • Muscle cramps 
  • Altered mental status
  • Agitation
  • Seizures and coma

Along with symptoms, a clinician should also inquire about medical history of pulmonary or central nervous system (CNS) disorders, all home medications, and social history indicators. 

View the full review. 


Rondon-Berrios, Helbert; Agaba, Emannuel I; Tzamaloukas, Antonios H. “Hyponatremia: pathophysiology, classification, manifestations and management.” International Urology and Nephrology, Nov. 2014.

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