Fluid and Electrolyte Imbalance: Hyponatremia


  • Sodium is essential to maintain osmotic pressure and acid-base balance chemically and to transmit nerve impulses.
  • Sodium levels are obtained through venous blood extraction.
  • It is a metabolic disorder wherein the level of sodium in the blood is lower than normal (< 135 mEq/L).
  • It is a result of one of the following:
    • Severe burns
    • Congestive heart failure
    • Excessive fluid loss such as severe diarrhea, vomiting
    • Excessive IV induction of nonelectrolyte fluids such as glucose
    • Addison’s disease
    • Severe nephritis
    • Pyloric obstruction
    • Malabsorption syndrome
    • Diabetic acidosis
    • Drugs such as diuretics
    • Edema
    • Large amounts of water per orem
    • Hypothyroidism
    • Excessive ADH production


  • altered mental status, restlessness
    • convulsions
    • fatigue, headache, irritability
    • satiety
    • muscle spasms or cramps
    • muscle weakness
    • nausea, vomiting
    • restlessness


  • Correct underlying disorder associated with hyponatremia.
  • Intravenous fluid administration.
  • Give sodium tablets.
  • Water restriction.
  • When exercising, keep hydrated.

Nursing Considerations:

  1. Strictly monitor fluid intake and output.
  2. Observe for dehydration. Accurately record state of hydration.
  3. Observe for neuromuscular changes such as declining levels of consciousness, fatigue and muscular weakness.
  4. Monitor for signs of edema and hypertension.
  5. Ensure adequate dietary sodium intake of 90 to 250 mEq/day.

Photo credits: www.health.howstuffworks.com

Daisy Jane Antipuesto RN MN

Currently a Nursing Local Board Examination Reviewer. Subjects handled are Pediatric, Obstetric and Psychiatric Nursing. Previous work experiences include: Clinical instructor/lecturer, clinical coordinator (Level II), caregiver instructor/lecturer, NC2 examination reviewer and staff/clinic nurse. Areas of specialization: Emergency room, Orthopedic Ward and Delivery Room. Also an IELTS passer.

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