From the Guidelines
Hyponatremia typically presents with symptoms such as headache, nausea, vomiting, fatigue, muscle cramps, and general weakness when serum sodium levels fall below 130 mEq/L, with more severe symptoms like confusion, irritability, disorientation, and altered mental status occurring at levels below 125 mEq/L. The severity and rapidity of onset of hyponatremia influence the clinical presentation, with acute hyponatremia (developing within 48 hours) causing more severe neurological symptoms than chronic hyponatremia due to the brain's inability to adapt to the rapid change in sodium levels 1.
Signs and Symptoms
The signs and symptoms of hyponatremia can vary widely among patients but generally include:
- Headache
- Nausea
- Vomiting
- Fatigue
- Muscle cramps
- General weakness
- Confusion
- Irritability
- Disorientation
- Altered mental status Severe hyponatremia can lead to life-threatening complications such as seizures, coma, and death due to brain swelling 1.
Risk Factors
Several factors can increase the risk of developing hyponatremia, including:
- Certain medications (diuretics, antidepressants, antipsychotics)
- Excessive water intake
- Heart failure
- Kidney disease
- Liver disease
- Endocrine disorders like SIADH or adrenal insufficiency Elderly patients may present with nonspecific symptoms like falls or gait disturbances 1.
Underlying Mechanism
The underlying mechanism of hyponatremia involves water moving into brain cells when extracellular sodium is low, causing cellular swelling and increased intracranial pressure, which explains the neurological manifestations of this electrolyte disturbance 1.
Management
The management of hyponatremia depends on its severity and the underlying cause. For mild hyponatremia (Na 126-135 mEq/L) in cirrhosis without symptoms, no specific management apart from monitoring and water restriction is recommended 1. For more severe cases, water restriction, cessation of diuretics, and albumin infusion may be necessary, with hypertonic saline reserved for short-term treatment of patients with symptomatic or severe hyponatremia or those with imminent liver transplant 1.
From the Research
Signs and Symptoms of Hyponatremia
The signs and symptoms of hyponatremia can range from mild to severe and life-threatening. Some of the common symptoms include:
- Nausea and vomiting 2, 3, 4
- Weakness and fatigue 2, 3, 4
- Headache 3
- Mild neurocognitive deficits, such as lack of concentration and forgetfulness 3, 4
- Loss of balance and gait disturbances 2, 4
- Seizures and coma in severe cases 2, 3, 4, 5, 6
- Delirium and confusion 3, 5
- Impaired consciousness and ataxia 3, 5
Severity of Hyponatremia
The severity of hyponatremia is classified based on the serum sodium level:
- Mild hyponatremia: 130-134 mEq/L 3, 4
- Moderate hyponatremia: 125-129 mEq/L 3
- Severe hyponatremia: less than 125 mEq/L 3, 4, 5, 6
Factors Affecting Symptom Severity
The severity of symptoms depends on: