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Sodium High

Hypernatremia is a condition, characterized by increased levels of sodium in the blood, beyond 145 mmol/L. It is serious condition requiring prompt medical attention.


Individuals with hypernatremia in the initial stages suffer from lethargy, onset of edema, excitability, weakness and irritability. As the condition progresses to more advanced stages, there is onset of seizures and the patient can even enter the comatose stage. Severe symptoms are primarily experienced due to increase in level of serum sodium above 157 mEq/L. When the levels rise beyond 180 mEq/L in adults, then it can be a significant cause of mortality [6].

Wound Infection
  • We followed the patients for 30-day perioperative outcomes, which included death, major coronary events, wound infections, pneumonia, and venous thromboembolism.[ncbi.nlm.nih.gov]
Fever of Unknown Origin
  • Abstract The authors describe a 2-year-old boy with a clinical presentation of prolonged fever of unknown origin and severe hypernatremia. This rare association was the result of a hypothalamic/third ventricle tumor.[ncbi.nlm.nih.gov]
Prolonged Immobilization
  • CONCLUSIONS: Chronic hypernatremia in patients with prolonged immobilization is associated with an increased risk for development of deep venous thrombosis. Copyright 2004 S. Karger AG, Basel[ncbi.nlm.nih.gov]
  • Abstract The authors describe a patient with an unusual combination of polydipsia and isolated hypernatremia without any other changes of electrolytes. The patient had two attacks of hypernatremia which were successfully treated with clozapine.[ncbi.nlm.nih.gov]
  • Typical DI symptoms such as polydipsia, polyuria, and marked thirst are concealed in these cases, because the hypothalamic "thirst center" cannot send thirst stimuli to the cerebral cortex.[ncbi.nlm.nih.gov]
  • She had a recent history of polyuria and polydipsia. Magnetic resonance imaging of her brain revealed hydrocephalus due to possible craniopharyngioma.[ncbi.nlm.nih.gov]
  • Defects in AVP secretion and/or synthesis produce central diabetes insipidus (DI), polyuria with polydipsia, hypernatremia and hyperosmolality.[ncbi.nlm.nih.gov]
  • Many cases of diabetes insipidus involve polydipsia, which means excessive thirst, but when sodium levels are increased, the opposite effect may occur. This generally occurs with central diabetes insipidus only.[diabetesinsipidus.org]
Psychomotor Retardation
  • CASE REPORT: We report a new case of semilobar-HPE complicated by neurogenic hypernatremia and no signs of dehydration in a child with microcephaly, spasticity, mental and psychomotor retardation, frontal bones hypoplasia, and mild facial dysmorphism.[ncbi.nlm.nih.gov]
  • A 19-year-old man presented to the Emergency Department in a comatose state with seizure-like activity 2 hours after ingesting a quart of soy sauce.[ncbi.nlm.nih.gov]
  • In severe condition, individuals can experience seizures or can even enter the comatose stage. Diagnosis: Determining the serum sodium levels forms the preliminary base of diagnostic profile.[symptoma.com]
  • Even severe hypernatremia might not inevitably lead to central nervous system dysfunction and seizures in extremely low birth weight infants. Copyright 2009 S. Karger AG, Basel.[ncbi.nlm.nih.gov]
  • In all cases, symptoms of cerebral damage such as seizures, fever and somnolence developed within hours after salt ingestion. All individuals were admitted to hospital before their deaths.[ncbi.nlm.nih.gov]
  • Manifestations include confusion, neuromuscular excitability, hyperreflexia, seizures, and coma.[web.archive.org]
  • The most important signs result from brain cell shrinkage and include confusion, muscle twitching or spasms.[en.wikipedia.org]
  • Symptoms of hypernatremia include: Extreme thirst Fatigue Confusion Low blood pressure Diet changes Limit all foods that are high in sodium, including: Canned soups Canned beans Frozen dinners Commercially prepared tomato sauce and spaghetti sauce Pizza[fairview.org]
  • Keep patient safe because they will be confused and agitated. Doctor may order to give isotonic or hypotonic solutions such as 0.45% NS (which is hypotonic and most commonly used).[registerednursern.com]
Altered Mental Status
  • Hypernatremia due to water loss occurs only in patients who can’t access water such as infants, elderly, patients with altered mental status and hypodipsia ( 5 ).The following conditions lead to water loss: Insensible loss Burns Hyperventilation Excessive[unboundmedicine.com]
  • The signs and symptoms include; altered mental status, lethargy, irritability, restlessness, seizures, muscle twitching, hyerreflexia, spasticity, fever, nausea, labored respiration, and intense thirst.[clinlabnavigator.com]
  • Such a type of condition commonly strikes the infants, individuals with altered mental status and the elderly population.[symptoma.com]
  • Patients with altered mental status. Those with hypothalamic lesions affecting sense of thirst (adipsia). Those with critical illness causing acute kidney injury and consequent inability to concentrate urine, or dependency on intravenous fluids.[patient.info]
Neonatal Seizures
  • In the study by Bolat et al. [ 10 ], a rate of SNa correction beyond 0.5 mEq/L/h was significantly associated with adverse outcomes, with an impressive odds ratio of 4.3 for death and neonatal seizures. In Erdemir et al.'[karger.com]
Fixed Pupils
  • The groups were similar except for lower GCS (p 0.002) and increased incidence of fixed pupil(s) on admission in both hypernatremia groups (p[ncbi.nlm.nih.gov]


An elevated serum sodium level of greater than 145 mEq/L confirms the diagnosis of hypernatremia. Laboratory studies are indicated in such cases, which include determining levels of urea, creatinine, glucose, serum and urine electrolytes. In addition, 24 hour urine volume along with urine and plasma osmolality also needs to be determined.

Imaging studies such as MRI and CT scan of the brain are indicated if the patient has suffered head injuries or trauma or shows signs of central diabetes insipidus. Histologic findings are of no significance unless vital signs indicate presence of central diabetes insipidus.

  • Laparoscopy could play a crucial role in Na absorption due to high intraabdominal pressure caused by the pneumoperitoneum and its limitations to avoid peritoneal absorption of hypertonic saline solution.[ncbi.nlm.nih.gov]


Treatment of hypernatremia is based on 4 goals, including recognizing the symptoms, determining the underlying disease, correcting the disturbances in volume and correction of hypertonicity [7].

The sodium levels are gradually brought to normal because rapid correction of volume can get very dangerous. This is so because, the brain very readily adapts to the increased sodium concentration. As a result of this, when the sodium levels are rapidly brought to normal, then water can enter the brain cells causing them to swell and giving rise to conditions like cerebral edema and seizures which can turn life threatening and cause permanent damage to brain [8].

Chronic cases of hypernatremia with mild or no symptoms are corrected at rate of 0.5 mEq/L/h and a total of 8-10mEq/L should be given in 24 hour period. Diurertic therapy is indicated in patients suffering from nephrogenic diabetes insipidus. Several drugs such as clofibrate, chlorpropamide and carbamazepine are given to patients with central diabetes insipidus to increase the hormone arginine vasopressin [9].


The prognosis of hypernatremia is good, unless an underlying neurological condition is causing the condition. The rate of mortality associated greatly depends on the severity of the condition; with a rate of 40 to 70% seen in elderly patients with severe hypernatremia [5].


Inadequate intake of water is the major cause of hypernatremia, which can occur due to the following factors [2]:

  • Conditions of diarrhea
  • Loss of water through the urinary tract, which occurs due to glycosuria or osmotic diuretics
  • Water loss due to excessive sweating
  • Diabetes, which favors excessive water excretion from kidneys; wherein there is either inadequate production of the hormone vasopressin or the kidneys do not adequately respond to the hormone
  • Hypernatremia can also occur in those individuals who consume excessive amounts of sea water or products containing high concentration of sodium, such as soy sauce


It has been estimated that, in the US, the incidence of hypernatremia amongst the hospitalized population is 0.3 to 5.5%. Research has pointed towards the fact that, more than 60% cases of hypernatremia are acquired. Very low incidence of 0.12 to 1.4% of hypernatremia is recorded upon hospital admission. Critically ill patients are also at high risk of contracting the disorder due to factors such as sedation, coma or ventilation.

A high mortality rate of 30 to 48% has been recorded in patients admitted to intensive care unit. Such patients had serum sodium levels of more than 150 mmol/L [3].

Patients admitted to hospital due to severe sepsis, were found to develop hypernatremia within the first 5 days of hospital admission. The basic reason behind this was the 0.9% of saline that was given during the first 48 hours, which led to an increase in sodium concentration.

Sex distribution
Age distribution


Hypernatremia primarily occurs due to water loss or sodium gain that essentially results from various factors. Researchers and clinicians have strongly put forth the fact that hypernatremia is a water problem and majorly occurs due to the phenomenon of decrease in total body water. In view of this, conditions favoring such a type of event cause an increase in the sodium concentration, leading to hypernatremia.

Under normal physiologic conditions, thirst and release of arginine vasopressin are triggered by increase in fluid osmolality of body beyond 280 to 290 mOsm/L. This osmotic threshold is similar for conditions of thirst as well as release of arginine vasopressin hormone. When there is an increase in the osmolality, water is drawn from the cells, which causes dehydration of the neurons in the brain, known as tonicity receptors. Upon stimulation, signals are sent to parts of brain to trigger thirst and the simultaneous release of the hormone arginine vasopressin. Such sequence of events causes increased consumption of water and increased urinary concentration, thereby correcting the hypernatremic state [4].


Maintenance of proper fluid balance forms the basis of preventing hypernatremia. Replenishing for lost fluids after heavy physical activity or exercise should be done. Infants and children should be fed water after short intervals. Elderly patients who are critically ill or are unable to fetch water for themselves should be taken care of and given water in between intervals [10].


Hypernatremia is primarily caused due to significant decrease in total body water. Due to this reason, hypernatremia often corresponds with dehydration. Such a type of condition commonly strikes the infants, individuals with altered mental status and the elderly population. The reason being, in these groups of population, the thirst mechanism is intact but they are not in a position to ask for water or help themselves [1].

Patient Information

Definition: Hypernatremia is a condition, characterized by increased serum sodium level above 145 mmol/L. The condition is a common occurrence in the infant and elderly population. It has also been noted that, majority of hospitalized patients are also susceptible to acquire hypernetremia.

Cause: It practically occurs due to reduction in total body water and does not occur due to sodium homeostasis. Factors that induce water loss include excessive sweating, diarrhea, excess of mineral corticoid due to disease such as Conn’s syndrome, salt poisoning and excess secretion of water by kidney in disease conditions such as diabetes insipidius.

Symptoms: Symptoms of hypernatremia include persistent lethargy, undue fatigue, weakness, edema and neuromuscular excitability. In severe condition, individuals can experience seizures or can even enter the comatose stage.

Diagnosis: Determining the serum sodium levels forms the preliminary base of diagnostic profile. In addition, various laboratory studies such as measuring the glucose levels, serum and urine electrolytes, urea, creatinine, 24 hour urine volume and levels of plasma hormone arginine vasopressin are also required.

Treatment: Treatment of hypernatremia is geared towards normalizing the serum sodium levels by increasing the total body water. This is done by administration of water either orally or through intravenous route. However, water alone cannot be given and therefore, it given through dextrose or saline solution.



  1. Snyder NA, Feigal DW, Arieff AI. Hypernatremia in elderly patients. A heterogeneous, morbid, and iatrogenic entity. Ann Intern Med 1987; 107:309.
  2. Bhave G, Neilson EG. Body fluid dynamics: back to the future. J Am Soc Nephrol. Dec 2011;22(12):2166-81
  3. Darmon M, Timsit JF, Francais A, et al. Association between hypernatraemia acquired in the ICU and mortality: a cohort study. Nephrol Dial Transplant. Feb 17 2010
  4. Boone M, Deen PM. Physiology and pathophysiology of the vasopressin-regulated renal water reabsorption.Pflugers Arch. Sep 2008;456(6):1005-24.
  5. Adrogué HJ, Madias NE. Hypernatremia. N Engl J Med 2000; 342:1493.
  6. Kumar S, Berl T. Sodium. Lancet. Jul 18 1998;352(9123):220-8.
  7. Fried LF, Palevsky PM. Hyponatremia and hypernatremia. Med Clin North Am. May 1997;81(3):585-609.
  8. Alshayeb HM, Showkat A, Babar F, et al. Severe hypernatremia correction rate and mortality in hospitalized patients. Am J Med Sci 2011; 341:356.
  9. Bockenhauer D, van't Hoff W, Dattani M, et al. Secondary nephrogenic diabetes insipidus as a complication of inherited renal diseases. Nephron Physiol. 2010;116(4):p23-9.
  10. Henkin SD, Sehl PL, Meyer F. Sweat rate and electrolyte concentration in swimmers, runners, and nonathletes. Int J Sports Physiol Perform 2010; 5:359. 

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Last updated: 2018-06-22 11:53