Hypernatremia occurs when sodium levels in the blood are too high. Sodium plays an essential role in various bodily functions, such as fluid balance, muscle contraction, and nerve impulse generation. Most of the sodium in the body is in the blood and lymph fluid.

An excess of sodium in the blood can sometimes become a problem if it goes untreated. Although hypernatremia is often mild and does not usually require treatment, moderate-to-severe cases may require attention.

Keep reading for more information on the causes, symptoms, and treatment of hypernatremia.

a woman with a glass of water that she is going to drink to help with her hypernatremiaShare on Pinterest
A person with hypernatremia may experience excessive thirst.

Hypernatremia occurs when the serum sodium concentration is higher than 145 milliequivalents per liter (mEq/l). It means that the level of sodium in a person’s blood is too high.

Two common causes of hypernatremia are insufficient fluid intake and too much water loss. In rare cases, consuming too much sodium can cause hypernatremia to occur.

The opposite of hypernatremia is hyponatremia. This condition occurs when a person’s serum sodium level is less than 135 mEq/l. In other words, hyponatremia develops when too little sodium is in the blood.

Sodium is an electrolyte that plays an essential role in regulating the levels of water and other substances in the body. The kidneys and adrenal glands are responsible for regulating sodium levels.

The adrenal gland produces a hormone called aldosterone. This hormone and the kidneys work together to maintain the balance of sodium in the blood.

Changes in water loss or water intake also change the concentration of sodium in the blood. Receptors in the brain recognize the need for level corrections. The body will respond by either increasing thirst (to boost water intake) or passing a greater amount of sodium in the urine (to excrete more sodium).

Hypernatremia may not cause any symptoms, meaning that a person may not be aware that they have it.

The main symptom of hypernatremia is excessive thirst. Other symptoms include fatigue and confusion.

In advanced cases, a person may experience muscle twitching or spasms, as sodium is important for the function of muscles and nerves. With severe elevations of sodium, seizures and coma may occur.

The primary causes of hypernatremia are too much sodium or insufficient liquid in the blood.

Several conditions can cause hypernatremia or increase its likelihood. These include:

Certain people are more likely than others to develop hypernatremia. At-risk populations include:

  • people receiving intravenous (IV) treatments or undergoing nasogastric feeding
  • people with an altered mental state
  • infants
  • older adults

In most cases, an underlying health condition, such as kidney disease or diabetes, will cause a person’s hypernatremia.

A doctor can often make a diagnosis by asking about the person’s medical history and carrying out a physical examination.

If the doctor suspects hypernatremia, they may run blood or urine tests. Both tests can show an increased presence of sodium in the blood, which can indicate hypernatremia.

All treatment for hypernatremia involves correcting the fluid and sodium balance in the body. Doing this usually means treating the underlying condition that is causing the increased blood sodium levels.

The type of treatment will vary depending on the underlying cause. For example, if a person is finding it difficult to manage their diabetes, their doctor will likely recommend steps to get the condition under control.

Other treatment options for hypernatremia may include simply increasing fluid intake.

In mild cases, increasing water consumption can help restore the proper balance of sodium in the blood.

In more severe cases, a person may need IV fluids to help restore proper sodium levels. They may also require a doctor to monitor whether their sodium levels are improving and adjust the fluid concentration accordingly.

Without treatment, hypernatremia can lead to serious complications.

One of the most dangerous complications is a brain hemorrhage, which can occur due to veins rupturing in the brain. Untreated hypernatremia has a mortality rate of 15–20%.

If a person has unexplained fatigue, irritability, or other mood changes, they should talk to their doctor, as these may be symptoms of hypernatremia.

Often, a person will not realize that they have the condition until their doctor examines them or runs a blood or urine test.

When a doctor diagnoses and treats hypernatremia early, the outlook for people with this condition is generally good.

People usually recover with minimal intervention. Often, a person can self-treat their condition at home by increasing their fluid intake. In other cases, they may need treatment in a hospital setting.

The success of treatment often relies on controlling the underlying condition. Treating the underlying condition should usually resolve hypernatremia.

Hypernatremia is when a person’s blood sodium levels are too high.

It typically occurs because a person has a decreased liquid intake or excessive fluid loss.

Certain people are more at risk than others of developing hypernatremia, including people in long-term care facilities and older people.

Treatment usually consists of increasing fluid intake and managing the underlying condition responsible for hypernatremia.