What are the symptoms of hyponatremia?

From the Guidelines

Hyponatremia symptoms vary depending on severity and how quickly sodium levels drop, with mild symptoms including headache, nausea, vomiting, fatigue, muscle cramps, and irritability, and more severe symptoms such as confusion, disorientation, seizures, and in severe cases, coma or death, typically appearing when blood sodium levels fall below 135 mEq/L and becoming more pronounced below 130 mEq/L, as noted in a study published in the journal Chest 1.

Symptoms of Hyponatremia

The symptoms of hyponatremia can be categorized based on the severity and acuity of the condition.

• Mild symptoms:
  • Headache
  • Nausea
  • Vomiting
  • Fatigue
  • Muscle cramps
  • Irritability
• Severe symptoms:
  • Confusion
  • Disorientation
  • Seizures
  • Coma or death These symptoms occur because low sodium causes water to move into cells, including brain cells, causing them to swell, leading to cerebral edema, which is what leads to the neurological symptoms, as explained in a study published in the journal Hepatology 1.

Factors Influencing Symptom Severity

The severity of symptoms is influenced by the rate at which sodium levels drop, with acute hyponatremia (developing within 48 hours) tends to cause more severe neurological symptoms than chronic hyponatremia, because the brain hasn't had time to adapt to the lower sodium levels, as noted in a study published in the journal Clinical and Molecular Hepatology 1.

Special Considerations

Elderly patients may present with balance problems and falls, while athletes might experience exercise-associated hyponatremia with symptoms appearing during or shortly after intense physical activity, as mentioned in a study published in the journal Gut 1.

Importance of Medical Attention

If you experience these symptoms, especially after excessive water intake, intense exercise, or while taking medications that affect fluid balance, seek medical attention promptly, as emphasized in a study published in the journal Circulation 1.

From the Research

Symptoms of Hyponatremia

The symptoms of hyponatremia can range from mild to severe and life-threatening. Some common symptoms include:

• Nausea and vomiting 2, 3, 4, 5, 6
• Weakness and fatigue 2, 3, 4, 5, 6
• Headache 3, 4, 6
• Mild neurocognitive deficits 2
• Gait disturbances and increased rates of falls and fractures 2
• Seizures and coma in severe cases 2, 3, 4, 5, 6
• Delirium, confusion, and impaired consciousness 3, 5
• Ataxia 3
• Brain herniation and death in rare cases 3

Severity of Symptoms

The severity of symptoms depends on the rapidity of development, duration, and severity of hyponatremia. Mild chronic hyponatremia may be associated with cognitive impairment, gait disturbances, and increased rates of falls and fractures 2. Severe hyponatremia can cause more severe symptoms such as seizures, coma, and death 2, 3, 4, 5, 6.

Classification of Hyponatremia

Hyponatremia can be classified into three types based on fluid volume status:

• Hypovolemic hyponatremia: treated with normal saline infusions 2, 3, 4, 6
• Euvolemic hyponatremia: treated with fluid restriction, salt tablets, or intravenous vaptans 2, 3, 4, 6
• Hypervolemic hyponatremia: treated primarily by managing the underlying cause and restricting fluid intake 2, 3, 4, 6