Hypervolemic Hyponatremia

Hypervolemic Hyponatremia: What You Need to Know

Hypervolemic hyponatremia is a type of low sodium condition in which excess water retention in the body leads to a decrease in sodium levels. It is a common complication of heart failure, kidney disease, and cirrhosis, and can cause a wide range of symptoms due to the body’s inability to regulate the balance of electrolytes. In some cases, it can be fatal if not properly managed.

The body needs a certain amount of sodium to maintain its normal functions. When the sodium level drops below 135 mEq/L, it is considered to be low, which can be caused by hypervolemic hyponatremia. Symptoms of this condition include confusion, nausea, vomiting, headache, muscle cramps, difficulty concentrating, and fatigue.

Hypervolemic hyponatremia is usually associated with another medical condition, such as congestive heart failure or kidney disease. Sometimes, however, it can be caused by medications, such as diuretics or antiseizure drugs, or by drinking too much water. Treatment includes limiting fluids and correcting the underlying problem.

Signs and Symptoms

The signs and symptoms of hypervolemic hyponatremia can range from mild to severe. Early signs of hyponatremia include headache, nausea, vomiting, confusion, muscle cramps, and difficulty concentrating. As the condition progresses, it can lead to seizures, coma, and in rare cases, death.

Risk Factors

Some people have a higher risk of developing hypervolemic hyponatremia. Those who are most at risk include:

  • Elderly individuals
  • Infants and young children
  • People with certain medical conditions, such as heart failure, kidney disease, and cirrhosis
  • People taking certain medications, such as diuretics or antiseizure drugs
  • People engaging in vigorous exercise

Diagnosis and Testing

Diagnosis of hypervolemic hyponatremia is based on the patient’s medical history, physical exam, and laboratory tests. Blood tests can measure electrolyte levels, and imaging tests, such as an MRI or CT scan, can reveal an underlying medical condition. Urine tests can also detect any medications that could be causing the problem.


Treatment for hypervolemic hyponatremia depends on the underlying cause. It may involve IV fluids, medications, or dialysis. The goal of treatment is to reduce symptoms and maintain electrolyte balance. Treatment should be tailored to the individual patient’s needs.


While there is no sure-fire way to prevent hypervolemic hyponatremia, the following steps may reduce the risk:

  • Monitor fluid intake to make sure it is balanced with urinary output
  • Pay attention to electrolyte levels and monitor for changes
  • Avoid using diuretics unless absolutely necessary
  • Drink plenty of fluids when engaging in vigorous exercise
  • Talk to your doctor about any medications you are taking