Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatment
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Hypernatremia is an elevated concentration ofsodium ions in the bloodthat can happen after decreased fluid intake. These sodium ions are the same type of substance found as a component of table salt (sodium chloride). Sodium ions are the most common ion found outside cells and in the bloodstream, but it’s not good when there are too many in the blood.
Hypernatremia may not cause any symptoms, but it can increase the risk of other medical problems and even death. Hypernatremia is an especially big problem in hospitalized patients, where it may affect around 2% of people admitted.
Even more people may have hypernatremia at some point during hospitalization. Infants and older people are particularly at risk of a dangerously high sodium level. Blood tests can tell you what your levels are, but other tests may be needed to determine the underlying cause.
This article covers the symptoms and causes of hypernatremia, including at-risk populations. It also explains how healthcare providers diagnose and treat high sodium levels.
Simon Jarratt/ Corbis/ VCG/ Corbis/ Getty Images Plus/ Getty Images
Hypernatremia Symptoms
People with hypernatremia may not have any symptoms, especially if the concentration of sodium has been rising gradually.
In infants, hypernatremia might cause symptoms such as the following:
An adult with hypernatremia might have somewhat different types of symptoms, like:
Symptoms of hypernatremia are more likely to be severe if the level of sodium gets exceptionally high. Symptoms are also more likely if a person has developed hypernatremia suddenly instead of developing it gradually. (This latter is more common.)
Hypernatremia occurs in about 1% to 4% of people who are hospitalized. Hospitalized patients who have it tend to have a higher risk of medical complications and death compared to people who don’t have hypernatremia. People with hypernatremia are also more likely to be discharged to hospice or a nursing facility.
One possible complication of hypernatremia isintracranial bleeding(bleeding inside the brain). This can happen when hypernatremia causes brain cells to shrink in size, increasing the chance of a blood vessel breaking in the brain.This is the most serious potential complication of hypernatremia.
Hypernatremia Causes
The body has its own way of keeping the right levels of sodium in the blood. However, sometimes the body fails to keep the sodium concentration within a normal range. When the concentration gets too high, that’s calledhypernatremia. (Hyponatremiais another problem, in which the concentration gets too low. It has different causes and leads to other potential problems.)
Importance of Sodium Concentration
Having the right concentration of sodium in the blood is very important for your body. This is critical for the way your body regulates how much water is inside cells. This helps make sure that they don’t swell excessively or contract too much. It is also important to keep yourblood pressurein the right range. The sodium in your blood also plays complex roles in supporting nerve cell function and in the transport of materials into and out of cells.
How Much Water Should You Drink a Day?
Specific Causes of Hypernatremia
Inadequate intake of water has a number of different possible causes. Water simply might not be available. Or, for a variety of reasons, a person might not be drinking as much as they should. This might happen, for example, from some of the following:
Certain medications may also cause hypernatremia as a side effect. These includelithium, phenytoin, and amphotericin.
Populations at Risk
Infants and older people are most susceptible to hypernatremia. Obviously, infants are not able to control their own intake of fluids. They also have a high surface area compared to their weight, which makes them susceptible to increased water loss. They may easily become dehydrated from a stomach bug or if they are having trouble with breastfeeding.
Older people tend to have a less sensitive thirst response, reduced ability to form concentrated urine, and decreased water stores. They may also have additional medical conditions that increase risk, or they may take medications with potential side effects of hypernatremia.
Hypernatremia and Diet
How Hypernatremia Is Diagnosed
Getting a blood test is the only way to know what your sodium levels are. However, other diagnostic tests may be needed to help nail down the cause of high sodium in the blood.
Blood Levels
A blood sodium test is needed to diagnose hypernatremia. When this test is used, hypernatremia is usually defined as having a serum sodium greater than 145 milliequivalents per liter (mEq/L). Severe symptoms are most likely to happen if a person’s sodium is even higher, say 160 or more.
The blood sodium test is usually performed along with other basic tests for electrolytes and other important blood products.
Medical History, Exam, and Other Lab Tests
The clinician must also diagnose the underlying cause of the elevated sodium. That’s important because different underlying causes have different treatments.
The medical history is critically important. The clinician needs to know about symptoms, when they started, and other medical problems. A medical exam is also a key component of diagnosis. For example, a healthcare provider might noticesigns of dehydrationlike dry mouth or flaccid-appearing skin.
Often, a clinician can make a diagnosis of the underlying cause with the help of the medical history and clinical exam alone. For example, if it’s known that a person hasn’t been drinking enough water, the cause of hypernatremia is usually clear. But some of the time, additional tests may be needed. These may differ depending on the surrounding circumstances. These might include:
Depending on the context and available clues, other tests might be needed. For example, your clinician might see how well your body makes concentrated urine in response to desmopressin (which acts like ADH). This can help your clinician diagnose different kinds ofdiabetes insipidus, if present. Or some people might need a CT scan of their head, to make sure a brain bleed isn’t present.
How Do You Correct Hypernatremia?
Treatment of hypernatremia depends somewhat on the underlying cause. It’s important to address whatever caused the elevated sodium to begin with. For example, someone with central diabetes insipidus might need to be treated with desmopressin. It’s also important to evaluate whether a medication might be the cause of the hypernatremia.
It’s critical to replenish any lost fluids. Sometimes this can just be done orally. Other times, a person will need to receive intravenous fluids to increase the amount of water in their blood (and therefore decrease the concentration of sodium).
It’s important that your medical team correct hypernatremia gradually. Overly rapid treatment of hypernatremia can cause brain swelling in some cases.Seizuresare another possible risk. So it’s critical that your healthcare team give your body a chance to adapt. In people who had had hypernatremia that developed over a long period of time, treatment with fluids needs to be more gradual than in people who developed it more rapidly.
You’ll also need repeated monitoring of sodium levels in the blood, to make sure the levels go back to normal with treatment.
Summary
Hypernatremia is a medical situation that needs to be taken seriously. It may or may not cause symptoms, which can include increased thirst, nausea and vomiting, and muscle weakness.
You can have high sodium levels because you’re not getting enough fluid and/or you’re losing too much. Infants and older people are most at risk, especially those staying in the hospital.
Healthcare providers run a blood test to check sodium levels. If you have high sodium levels, additional diagnostic tests may be needed to rule out other conditions like kidney disease. Talk your healthcare team about how exactly they plan to correct hypernatremia.
7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Arampatzis S, Frauchiger B, Fiedler GM, et al.Characteristics, symptoms, and outcome of severe dysnatremias present on hospital admission.Am J Med. 2012;125(11):1125.e1-1125.e7. doi:10.1016/j.amjmed.2012.04.041Braun MM, Barstow CH, Pyzocha NJ.Diagnosis and management of sodium disorders: hyponatremia and hypernatremia.Am Fam Physician. 2015;91(5):299-307.Rondon-Berrios H, Argyropoulos C, Ing TS, et al.Hypertonicity: Clinical entities, manifestations and treatment.World J Nephrol. 2017;6(1):1–13. doi:10.5527/wjn.v6.i1.1Arzhan S, Roumelioti ME, Litvinovich I, Bologa CG, Myers OB, Unruh ML.Hypernatremia in hospitalized patients: a large population-based study.Kidney360. 2022;3(7):1144-1157. doi:10.34067/KID.0000702022Strazzullo P, Leclercq C.Sodium.Adv Nutr. 2014;5(2):188–190. doi:10.3945/an.113.005215Mahabadi N, Naganathan S, Al-Dhahir MA.Hypernatremia. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.Shah MK, Workeneh B, Taffet GE.Hypernatremia in the geriatric population.Clin Interv Aging. 2014;9:1987–1992. doi:10.2147/CIA.S65214
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Arampatzis S, Frauchiger B, Fiedler GM, et al.Characteristics, symptoms, and outcome of severe dysnatremias present on hospital admission.Am J Med. 2012;125(11):1125.e1-1125.e7. doi:10.1016/j.amjmed.2012.04.041Braun MM, Barstow CH, Pyzocha NJ.Diagnosis and management of sodium disorders: hyponatremia and hypernatremia.Am Fam Physician. 2015;91(5):299-307.Rondon-Berrios H, Argyropoulos C, Ing TS, et al.Hypertonicity: Clinical entities, manifestations and treatment.World J Nephrol. 2017;6(1):1–13. doi:10.5527/wjn.v6.i1.1Arzhan S, Roumelioti ME, Litvinovich I, Bologa CG, Myers OB, Unruh ML.Hypernatremia in hospitalized patients: a large population-based study.Kidney360. 2022;3(7):1144-1157. doi:10.34067/KID.0000702022Strazzullo P, Leclercq C.Sodium.Adv Nutr. 2014;5(2):188–190. doi:10.3945/an.113.005215Mahabadi N, Naganathan S, Al-Dhahir MA.Hypernatremia. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.Shah MK, Workeneh B, Taffet GE.Hypernatremia in the geriatric population.Clin Interv Aging. 2014;9:1987–1992. doi:10.2147/CIA.S65214
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Arampatzis S, Frauchiger B, Fiedler GM, et al.Characteristics, symptoms, and outcome of severe dysnatremias present on hospital admission.Am J Med. 2012;125(11):1125.e1-1125.e7. doi:10.1016/j.amjmed.2012.04.041Braun MM, Barstow CH, Pyzocha NJ.Diagnosis and management of sodium disorders: hyponatremia and hypernatremia.Am Fam Physician. 2015;91(5):299-307.Rondon-Berrios H, Argyropoulos C, Ing TS, et al.Hypertonicity: Clinical entities, manifestations and treatment.World J Nephrol. 2017;6(1):1–13. doi:10.5527/wjn.v6.i1.1Arzhan S, Roumelioti ME, Litvinovich I, Bologa CG, Myers OB, Unruh ML.Hypernatremia in hospitalized patients: a large population-based study.Kidney360. 2022;3(7):1144-1157. doi:10.34067/KID.0000702022Strazzullo P, Leclercq C.Sodium.Adv Nutr. 2014;5(2):188–190. doi:10.3945/an.113.005215Mahabadi N, Naganathan S, Al-Dhahir MA.Hypernatremia. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.Shah MK, Workeneh B, Taffet GE.Hypernatremia in the geriatric population.Clin Interv Aging. 2014;9:1987–1992. doi:10.2147/CIA.S65214
Arampatzis S, Frauchiger B, Fiedler GM, et al.Characteristics, symptoms, and outcome of severe dysnatremias present on hospital admission.Am J Med. 2012;125(11):1125.e1-1125.e7. doi:10.1016/j.amjmed.2012.04.041
Braun MM, Barstow CH, Pyzocha NJ.Diagnosis and management of sodium disorders: hyponatremia and hypernatremia.Am Fam Physician. 2015;91(5):299-307.
Rondon-Berrios H, Argyropoulos C, Ing TS, et al.Hypertonicity: Clinical entities, manifestations and treatment.World J Nephrol. 2017;6(1):1–13. doi:10.5527/wjn.v6.i1.1
Arzhan S, Roumelioti ME, Litvinovich I, Bologa CG, Myers OB, Unruh ML.Hypernatremia in hospitalized patients: a large population-based study.Kidney360. 2022;3(7):1144-1157. doi:10.34067/KID.0000702022
Strazzullo P, Leclercq C.Sodium.Adv Nutr. 2014;5(2):188–190. doi:10.3945/an.113.005215
Mahabadi N, Naganathan S, Al-Dhahir MA.Hypernatremia. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.
Shah MK, Workeneh B, Taffet GE.Hypernatremia in the geriatric population.Clin Interv Aging. 2014;9:1987–1992. doi:10.2147/CIA.S65214
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
