What are the most common symptoms of hyponatremia (low sodium levels)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 14, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

The most common symptoms of hyponatremia include general weakness, confusion, headache, and nausea, which can progress to life-threatening manifestations such as seizures and coma if serum sodium levels drop below 120 mEq/L. These symptoms are determined by the degree of hyponatremia and the acuity of hypoosmolality 1. At serum sodium concentrations of 125 to 130 mEq/L, patients usually experience mild symptoms, while more severe symptoms occur at lower sodium levels.

Some key points to consider when evaluating hyponatremia symptoms include:

  • The severity of symptoms typically correlates with both how low the sodium level is and how quickly it developed 1
  • Acute hyponatremia tends to cause more severe symptoms than chronic hyponatremia because the brain hasn't had time to adapt to the osmotic changes
  • Early detection and appropriate management can prevent severe hyponatremia, which can lead to seizures, coma, and death 1
  • Hyponatremia in patients with small cell lung cancer is associated with shortened survival, highlighting the importance of prompt diagnosis and treatment 1

It's essential to investigate hyponatremia further by clinical assessment of intravascular volume status and biochemical measurements in blood and urine to determine the underlying cause and guide treatment 1. Recognizing these symptoms early is crucial as severe hyponatremia can be life-threatening if not properly treated.

From the Research

Common Symptoms of Hyponatremia

The symptoms of hyponatremia can vary depending on the severity of the condition. According to 2, 3, 4, 5, common symptoms of hyponatremia include:

  • Headache
  • Nausea
  • Vomiting
  • Weakness
  • Seizures
  • Confusion
  • Delirium
  • Impaired consciousness
  • Ataxia
  • Coma
  • Death

Severity of Symptoms

The severity of symptoms can range from mild to severe, depending on the level of sodium in the blood. Mild symptoms may include:

  • Mild neurocognitive deficits
  • Headache
  • Nausea
  • Vomiting Severe symptoms, on the other hand, may include:
  • Seizures
  • Confusion
  • Delirium
  • Impaired consciousness
  • Coma
  • Death

Clinical Manifestations

The clinical manifestations of hyponatremia can also vary depending on the underlying cause of the condition. According to 3, 5, hyponatremia can be classified into different types, including:

  • Hypovolemic hyponatremia
  • Euvolemic hyponatremia
  • Hypervolemic hyponatremia Each type of hyponatremia has its own set of clinical manifestations and treatment options.

Treatment Options

Treatment options for hyponatremia depend on the underlying cause and severity of symptoms. According to 2, 3, 6, treatment options may include:

  • Fluid restriction
  • Sodium supplementation
  • Diuretic therapy
  • Vasopressin receptor antagonists
  • Hypertonic saline infusions

Importance of Early Detection and Treatment

Early detection and treatment of hyponatremia are crucial to prevent complications and improve outcomes. According to 5, hyponatremia has been associated with increased morbidity and mortality, and prompt treatment can reduce the risk of death.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Hyponatremia: evaluation and management.

Hospital practice (1995), 2010

Research

Morbidity and Mortality of Hyponatremia.

Frontiers of hormone research, 2019

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.