Pediatric Hyponatremia Clinical Presentation

Updated: Apr 26, 2014
  • Author: Muthukumar Vellaichamy, MD, FAAP; Chief Editor: Timothy E Corden, MD  more...
  • Print


The history of patients with hyponatremia may include the following:

  • Hypotonic fluid use for maintenance hydration in hospitalized children (potential risk factor)
  • Feeding with hypotonic formula or excessive free water during infancy
  • Conditions that cause GI, Na-rich fluid loss, including the following:
    • Diarrhea
    • Vomiting
    • Fistulas
  • Renal disorders, including the following:
    • Salt-losing nephropathy
    • Acute renal failure
    • Chronic renal failure
  • Postoperative states [5]
  • Psychiatric conditions
  • Coma
  • Drug use
  • CNS and pulmonary diseases
  • Cirrhosis
  • Congestive heart failure
  • Acquired immunodeficiency syndrome (AIDS)


CNS findings

See the list below:

  • Early signs include the following:
    • Anorexia
    • Headache
    • Nausea
    • Emesis
  • Advanced signs include the following:
    • Impaired response to verbal stimuli
    • Impaired response to painful stimuli
    • Bizarre behavior
    • Hallucinations
    • Obtundation
    • Incontinence
    • Respiratory insufficiency
    • Seizure activity
  • Far-advanced signs include the following:
    • Decorticate or decerebrate posturing
    • Bradycardia
    • Hypertension or hypotension
    • Altered temperature regulation
    • Dilated pupils
    • Seizure activity
    • Respiratory arrest
    • Coma

Cardiovascular findings

See the list below:

  • Hypotension
  • Tachycardia

Musculoskeletal findings

See the list below:

  • Weakness
  • Muscular cramps


Hypervolemic hyponatremia (excess free-water retention)

See the list below:

  • Congestive heart failure
  • Cirrhosis
  • Nephrotic syndrome
  • Acute or chronic renal failure

Hypovolemic hyponatremia due to renal loss of sodium in excess of free-water

See the list below:

  • Diuretic excess
  • Osmotic diuresis
  • Salt-wasting diuresis
  • Adrenal insufficiency
  • Pseudohypoaldosteronism

Hypovolemic hyponatremia due to extrarenal loss of sodium in excess of free-water

See the list below:

  • GI conditions, such as the following:
    • Vomiting
    • Diarrhea
    • Drains
    • Fistula
  • Sweat
  • Cystic fibrosis
  • Cerebral salt-wasting syndrome (CSWS)
  • Third-spacing conditions, such as the following:

Normovolemic hyponatremia

See the list below:

  • Syndrome of inappropriate antidiuretic hormone secretion (SIADH)
    • Tumors - Adenocarcinoma of the duodenum, adenocarcinoma of the pancreas, carcinoma of the ureter, carcinoma of the prostate, Hodgkin disease, thymoma, acute leukemia, lymphosarcoma, or histiocytic lymphoma
    • Chest disorders - Infection (eg, tuberculosis or bacterial, mycoplasmal, viral, or fungal infection), positive-pressure ventilation, decreased left atrial pressure (eg, due to pneumothorax, atelectasis, asthma, cystic fibrosis, mitral valve commissurotomy, ligation of the patent ductus arteriosus ligation), or malignancy
    • CNS disorders - Infection (eg, tuberculous meningitis, bacterial meningitis, encephalitis), trauma, hypoxia-ischemia, psychosis, brain tumor, or miscellaneous CNS disorders (eg, Guillain-Barré syndrome, ventriculoatrial shunt obstruction, acute intermittent porphyria, cavernous sinus thrombosis, multiple sclerosis, anatomic abnormalities, vasculitis, stress, idiopathic causes)
    • Drugs (see image below)
      Drugs that impair water excretion. Drugs that impair water excretion.
  • Reset osmostat
  • Glucocorticoid deficiency
  • Hypothyroidism
  • Water intoxication due to intravenous (IV) therapy, tap-water enema, or psychogenic water drinking