Hypernatremia – Causes, Symptoms and Treatment

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A serum sodium level greater than 145 mEq/L is considered as Hypernatremia. The normal range of sodium in the blood is 136 – 145 mEq/L. Seizures and death are possible outcomes of severe Hypernatremia, with serum sodium levels above 152 mEq/L. 

A healthy blood sodium level is necessary for the body’s mineral and water balance, as well as the transmission of nerve impulses. Dehydration, convulsions, comas and even death can occur when the levels are too high.

The quantities of sodium and water in the body affect the concentration of sodium.

Water makes up about 60% of the human body weight and essentially exists in two fluid compartments—either outside of cells in extracellular fluid or inside cells in intracellular fluid.

The fluid in blood vessels, lymphatic vessels and the interstitial space—the area between cells that are filled with proteins and carbohydrates—all fall under the category of extracellular fluid.

By either losing more water than sodium or acquiring more sodium than water, a person with Hypernatremia may have a high concentration of sodium in the blood and extracellular fluid. In either case, this decreases the water content of the cells and raises the sodium concentration in the extracellular fluid. Hypernatremia gradually worsens over time.

How are sodium levels controlled?

When the body loses too much water or gains too much salt, Hypernatremia can occur. As a result, there is not enough bodily water for the amount of sodium in the body.

The control of sodium levels in the blood can be affected by changes in water intake or water loss. 

Fluid loss can occur due to

  • Drastic changes in thirst
  • Variations in urine composition

Brain receptors that detect the need for fluid or salt correction in healthy individuals trigger thirst and urine concentration. Normally, this causes an increase in the amount of salt excreted in the urine or an increase in water consumption. That will effectively treat Hypernatremia.

What are the symptoms of Hypernatremia?

Too much sodium in the blood can occur without symptoms, making the patient unaware of it.

However, there may be signs like

  • Spasms
  • Fatigue
  • Confusion
  • Restlessness
  • Extreme thirst
  • Excessive hunger 
  • Mood changes 
  • Muscle twitching 
  • Seizures 
  • Coma
  • Lethargy
  • Irritability
  • Unconsciousness

Particularly in young children, Hypernatremia can be quite dangerous. It can be caused by dehydration due to vomiting, diarrhoea, profuse sweating, severe burns or other underlying health issues.

Similarly, Hypernatremia can cause very severe problems in the elderly.

Causes of Hypernatremia

Water loss

This can be due to 

  • Stoma losses, such as diarrhoea and gastrointestinal losses
  • Skin loss (Excessive sweating/burns) 
  • Renal losses, such as those caused by intrinsic renal illness, post-obstructive diuresis, or when osmotic or loop diuretics are used.
  • The two most typical causes of osmotic diuresis are hyperglycemia and mannitol.
  • The lack of access to water, particularly for nursing infants, is due to a lack of milk production.

Less common causes

  • Diabetic nephropathy (central, nephrogenic, systemic disease, drugs)
  • High insensible losses
  • Reduced thirst due to underlying neurological issues or hypothalamic dysfunction

Excess Sodium

  • Consuming too much sodium (inappropriate formula concentration, high osmolality rehydration solutions, salt poisoning)
  • Iatrogenic (hypertonic saline, sodium bicarbonate) 


  • Primary Hyperaldosteronism (Conn’s Syndrome)
  • Secondary Hyperaldosteronism (CCF, nephrotic syndrome, steroids).

What are the risk factors of Hypernatremia?

Adults have this issue more frequently. A few other risk factors include,

  • Fever
  • Vomiting
  • Diarrhoea
  • Excessive sweating-related fluid loss
  • Using specific drugs that cause one to urinate more frequently
  • Severe burns
  • Having Diabetes or a renal condition.

How to diagnose Hypernatremia?

Mostly, Hypernatremia is caused by an underlying medical condition like diabetes or kidney disease.

A doctor may begin the diagnostic procedure by inquiring about a patient’s medical history and performing a physical examination.

They might perform blood or urine tests if they have hypernatremia suspicions. Both have a higher salt concentration.

Treating Hypernatremia

Hypernatremia can develop quickly (within 24 hours) or gradually over time (more than 24 to 48 hours). The doctor’s treatment approach will depend on how quickly symptoms appear.

Maintaining the body’s fluid and salt levels is the cornerstone of every treatment. Treatment for Hypernatremia that appears suddenly will be stronger than for Hypernatremia that onsets gradually.

If the disease is mild, one might be able to alleviate it by drinking more water. The patient is likely to be attached to an IV drip for more severe cases. That is used to intravenously hydrate the blood. 

Also, the doctor will keep an eye on the patient to see if the salt levels are rising, and if so, they might change the concentration of the fluid.


According to NCBI, Subarachnoid or subdural bleeding caused by bridging vein rupture and dural sinus thrombosis is the most adverse side effect of Hypernatremia. It may result in death or irreversible brain damage. Cerebral oedema, seizures and lasting brain damage result from chronic Hypernatremia that is corrected too quickly.

Hypernatremia prevention

Treating another health condition could sometimes result in Hypernatremia.

Also helpful in preventing Hypernatremia are,

  • Eating a wholesome, balanced diet.
  • Drinking adequate water to stay hydrated.
  • Increasing water intake in warmer weather or when exercising
  • Ensuring that any medical issues, such as kidney disease or diabetes, are properly controlled.


If a doctor detects hypernatremia early, the outlook is usually good. Hypernatremia is a condition in which the blood sodium level is too high. Usually, people recover with minimal intervention.

Sometimes, people can treat their condition by drinking more fluids. Sometimes, they may need medical care in a hospital setting.

Treatment for high blood pressure (hypertension) often relies on controlling the underlying condition, which then resolves the high blood pressure.


What is the main cause of Hypernatremia?

Although water loss is the main cause of Hypernatremia, it can also be brought on by consuming salt without water or by giving patients hypertonic sodium solutions. Dehydration is the term for Hypernatremia arising due to water loss.

What happens with Hypernatremia?

Usually, Hypernatremia makes a person thirsty. Dysfunction in the brain causes the most severe hypernatremia symptoms. Confusion, twitching muscles, seizures, coma, and even death can result from severe Hypernatremia.

What are the typical symptoms of Hypernatremia?

Excessive thirst is the primary sign of Hypernatremia. Fatigue, or excessive exhaustion, lack of energy and disorientation are other symptoms. Advanced cases may also result in muscle spasms or twitching.


The Information including but not limited to text, graphics, images and other material contained on this blog are intended for education and awareness only. No material on this blog is intended to be a substitute for professional medical help including diagnosis or treatment. It is always advisable to consult medical professional before relying on the content. Neither the Author nor Star Health and Allied Insurance Co. Ltd accepts any responsibility for any potential risk to any visitor/reader.

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