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Symptoms & Risks

Hyponatremia Symptoms, Complications, and Risks

Hyponatremia can result in poor patient outcomes due to the following complications and risks:

Adverse effects on the brain

Acute hyponatremia can adversely affect the brain and lead to severe neurologic consequences.1,2 These neurologic complications are often considered to be symptoms of acute or severe hyponatremia.2-4

Increased mortality risk

In an analysis of over 53,000 hospitalizations during a 7-year period, in-hospital hyponatremia was independently associated with in-hospital mortality.5

  • Hyponatremia was also independently associated with a greater length of hospital stay and discharge to a short-term or long-term care facility5
Increased falls and fractures

Hyponatremia in the elderly has been associated with increased falls and fractures.6-8

  • Bone fracture risk with hyponatremia is not only due to fall risk, but also due to an increase in bone fragility as a result of the hyponatremia9,10

Hyponatremia signs and symptoms can range from mild or nonspecific to severe

Mild or nonspecific signs and symptoms include the following3:

  • Confusion
  • Headache
  • Lethargy
  • Muscle aches
  • Nausea
  • Vomiting

Nonspecific or mild symptoms of hyponatremia may progress quickly to severe symptoms. The more severe symptoms are often neurologic complications due to brain edema and increased intracranial pressure from severe and rapidly evolving hyponatremia.2-4

These severe symptoms or complications include2-4:

  • Abnormal or severe somnolence
  • Respiratory arrest
  • Coma
  • Seizures

Some patients with hyponatremia are considered to be asymptomatic11

Patients considered to be asymptomatic may not be fully asymptomatic.2,5,8 There are many subtle signs or symptoms that may be present in “asymptomatic” chronic hyponatremia. These signs and symptoms include5-7,12:

These subtle signs can exist even in patients with mild hyponatremia.

  • A case-control study of 513 patients with bone fractures found that 13% (n=67) had hyponatremia (mean serum [Na+]: 131±3 mEq/L)6
    • The bone fractures in these patients were attributed to hyponatremia in 72.5% of all cases6

Osmotic Demyelination

Watch a video discussing osmotic demyelination and how it can occur with hyponatremia.