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EspañolHypernatremia symptoms: What are the early signs of hypernatremia?
Overview: What does hypernatremia look like?
Hypernatremia is an electrolyte imbalance in which the body’s sodium levels are too high for the amount of water in the body. It’s caused by dehydration—net water loss—or excessive sodium intake or retention. Dehydration is the most common reason people experience hypernatremia. Mild hypernatremia due to temporary dehydration is not a health threat. All it takes is a few drinks of water to get better. That’s not always the case. Severe dehydration or excessive salt can cause life-threatening hypernatremia. Severe hypernatremia, or a high sodium concentration in the blood, is uncommon among normally healthy people, mostly because thirst drives them to drink enough water. It’s more likely to happen to infants, older adults, people in nursing homes, and hospitalized patients.
Mild or moderate hypernatremia typically has no symptoms other than dehydration symptoms. When sodium levels are severely high, the first symptoms involve the nervous system, such as agitation, restlessness, lethargy, and sleepiness. Extremely high sodium levels can eventually lead to bleeding in the brain and permanent brain damage.
RELATED: Is salt bad for you? Here’s why scientists can’t agree
Key takeaways:
Hypernatremia due to dehydration is a common health condition that can affect anyone regardless of age, sex, race, or ethnicity. Severe hypernatremia mostly affects infants, older adults, the debilitated, and hospitalized patients.
Early signs of hypernatremia include dehydration symptoms, mood changes, lethargy, and somnolence.
Symptoms of severe hypernatremia, such as agitation, muscle twitching, stupor, seizures, and coma, may require immediate medical attention.
Hypernatremia is usually caused by dehydration (net water deficit) due to diarrhea, excess sweating, burns, kidney disease, high blood sugar, insufficient water intake, diabetes insipidus, impaired thirst, and medication side effects. Hypernatremia is also caused by too much sodium in the body due to rapid intake of large amounts of sodium (sodium poisoning), overuse of intravenous saline solution administration, overproduction of the hormone aldosterone (hyperaldosteronism), or medication side effects. You may be at risk for developing severe hypernatremia symptoms if you are an older adult, debilitated, in a nursing care facility, hospitalized, treated in an intensive care unit (ICU), or taking certain medications. Newborns and very young children are also at risk.
Hypernatremia requires a medical diagnosis.
Hypernatremia generally requires treatment. Hypernatremia symptoms typically resolve within a day to three days after starting treatment.
Treatment of hypernatremia may include drinking water, administering intravenous fluids, and treating the underlying cause.
Untreated hypernatremia could result in complications like brain hemorrhage, permanent brain damage, and death.
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What are the early signs of hypernatremia?
Healthcare professionals diagnose hypernatremia when the sodium concentration in the blood reaches a certain level: 145 milliequivalents of sodium per liter of blood (meq/l) or greater. Hypernatremia typically does not cause unique symptoms unless sodium levels get very high (more than 160 meq/l). If the cause is due to water deficit, the most common early signs of hypernatremia are symptoms of dehydration, including:
Thirst
Fatigue
Dry skin
Dry mouth
Dark urine
Decreased urination
Headache
Lightheadedness
Dizziness
Fainting
Fast heartbeat
Diabetes insipidus is a medical condition that causes both fluid loss and sodium retention, so hypernatremia is a common risk factor. The most common symptoms of diabetes insipidus that may be early signs of hypernatremia include:
Excessive thirst (polydipsia)
Excessive urination (polyuria)
Other early signs of hypernatremia may include:
Restlessness
Agitation
Irritability
Other hypernatremia symptoms
When sodium levels in the blood get very high, hypernatremia can cause symptoms distinct from dehydration symptoms. These symptoms will vary depending on age or the cause of hypernatremia. The most common symptoms of hypernatremia due to net water loss are:
Symptoms of dehydration
Mental changes such as confusion, irritability, lethargy, or stupor
Low blood pressure when sitting up or standing up (orthostatic hypotension)
Rapid heartbeats
Severe symptoms of hypernatremia include:
Muscle rigidity
Muscle jerking or twitching
Tremor
Seizures (sodium poisoning)
Coma
Hypernatremia symptoms in infants
Infants, especially newborns, are at a much higher risk for developing hypernatremia than adults. Among newborns younger than two weeks old, the incidence is close to 0.4%. The leading cause is inadequate water intake from breastfeeding. The likelihood of developing hypernatremia falls once infants are older than two weeks. In those cases, the most common cause of hypernatremia is water loss due to gut problems or infections.
In addition to dehydration symptoms, infants typically show other symptoms specific to hypernatremia, including:
Agitation
Irritability
Lethargy
Somnolence
High-pitched crying
Skin that feels doughy or velvety
Coma
Hypernatremia vs. hyponatremia symptoms
Mild to moderate cases of hypernatremia typically do not have symptoms unique from the underlying cause. Low sodium is also asymptomatic in mild or moderate cases. In severe cases, however, low sodium can severely affect how well organs and muscles function, so there are a variety of distinct symptoms.
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RELATED: Low sodium symptoms: what are the early signs of low sodium?
Types of hypernatremia: How can I tell which one I have?
High sodium seems simple. When sodium concentrations are high, that’s high sodium. That’s not quite right. High sodium levels are high relative to water levels in the body. There might be too much sodium or too little water. For that reason, healthcare providers distinguish between three types of high-sodium conditions. This distinction will determine the most appropriate treatment to correct the sodium imbalance.
Hypovolemic hypernatremia is high sodium caused by dehydration. People will experience symptoms of dehydration such as thirst, dry skin, dry lips, and tiredness. In most cases, the appropriate treatment is slow rehydration, typically by drinking water, but doctors may need to administer fluids intravenously.
Euvolemic hypernatremia involves normal water levels but too much sodium in the blood. It’s usually due to underlying medical conditions such as diabetes insipidus or medication adverse effects. Symptoms are usually symptoms of the underlying cause. In these cases, healthcare providers will endeavor to correct the underlying condition.
Hypervolemic hypernatremia involves too much water and way too much sodium. This is usually caused by intravenous fluid treatment in a hospital or ICU, but it can also be due to underlying conditions such as hyperaldosteronism. The most appropriate treatments are rehydration, loop diuretics, or, in life-threatening cases, dialysis.
When to see a doctor for hypernatremia symptoms
Hypernatremia, no matter what the cause, is a serious medical condition. Severe hypernatremia has a mortality rate of 60%. See a healthcare provider if there’s a concern that sodium levels are too high.
Healthcare providers usually identify the problem and its cause based on a medical history and a physical examination. To identify the cause, they may use blood tests to measure serum sodium levels and urine tests to measure the concentration of particles (osmolality) in the urine.
If the suspected cause is diabetes insipidus, the clinician may administer a water deprivation test. This will help distinguish between diabetes insipidus due to inadequate secretion by the pituitary gland of antidiuretic hormone (ADH or vasopressin), called central diabetes insipidus, and diabetes insipidus due to kidney abnormalities (nephrogenic diabetes insipidus).
Complications of hypernatremia
Untreated severe hypernatremia is usually fatal, but it’s very rare. Extremely high levels of sodium cause the brain to shrink. This shrinkage can cause bleeding in the brain. Complications include:
Permanent brain damage
Death
How to treat hypernatremia symptoms
Hypernatremia and its causes do require treatment. Severe cases involving adults usually occur in a hospital or managed care setting, so treatment will begin relatively quickly.
The primary goal of treatment is to restore the sodium and water balance in the body. This will typically involve:
Hydration: adding free water or isotonic water (water with the same sodium balance as body water) to the body orally or intravenously—rehydration usually proceeds slowly (48 to 72 hours) because rapid correction of serum sodium concentration can lead to fluid building up in the brain (cerebral edema), seizures, and permanent brain damage
Loop diuretics are used for sodium poisoning to rapidly reduce sodium levels as well as free water levels in the blood and tissues
The secondary goal of treatment is to correct the underlying cause. The most common treatments are:
Discontinuation of medications causing the problem
Desmopressin (DDAVP) or thiazide diuretics for diabetes insipidus
RELATED: Pituitary hormones: uses, common brands, and safety info
Signs hypernatremia is getting better
Mild or moderate cases of hypernatremia due to dehydration usually improve within a day. Severe hypernatremia can take up to three days to correct with slow rehydration. Lowering the serum sodium concentration by no more than 12 meq per day is a safe rate of rehydration. As water and sodium levels balance, symptoms of dehydration or hypernatremia will start to resolve.
Most importantly, stay hydrated
The most common cause of hypernatremia is dehydration. This can happen for many reasons. The surest way to prevent hypernatremia is to stay hydrated:
Drink fluids regularly throughout the day
Increase fluid intake if it’s hot
Increase fluid intake if exerting yourself or exercising
Avoid heat injury by staying indoors when it’s too hot outside, limiting outdoor physical activities, and wearing heat-appropriate clothing
Manage blood sugar levels if you have diabetes
The most vulnerable to hypernatremia due to water loss are infants, older adults, people in managed care, or people with dementia or psychiatric disorders. They’re at risk if they can’t take care of themselves. For caretakers, part of the job involves keeping these high-risk people hydrated throughout the day and protecting them from heat injury.
RELATED: 7 health benefits of drinking water
FAQs about hypernatremia symptoms
What are the neurological signs of hypernatremia?
Hypernatremia primarily affects the central nervous system, so the earliest signs of hypernatremia are typically neurological. These include agitation, restlessness, and irritability. As hypernatremia worsens, people may appear lethargic or sleepy. In extreme cases, hypernatremia can lead to coma or seizures.
Which drug is known to cause hypernatremia?
Several drugs can cause water loss out of proportion to sodium loss, causing hypernatremia. These include diuretics (water pills) and drugs that injure the kidneys, including tetracycline antibiotics, some antiviral drugs, lithium, amphotericin, and foscarnet. Some drugs can raise sodium levels in the body without affecting fluid levels. These include sodium chloride (salt pills), sodium bicarbonate, and N-acetylcysteine. Some drugs, such as corticosteroids and anabolic steroids, cause water loss and sodium retention.
RELATED: These sneaky meds could be the reason you’re so dehydrated
What is hypernatremia commonly associated with?
The most common cause of hypernatremia is dehydration. The most common medical condition associated with hypernatremia is diabetes insipidus, in which the body cannot control urination correctly, causing electrolyte imbalances.
What’s next? Additional resources for people with hypernatremia symptoms
Test and diagnostics
Adult dehydration, StatPearls
Diagnosis and management of sodium disorders: hyponatremia and hypernatremia, American Family Physician
Hypernatremia, Renal & Urology News
Hypernatremia, StatPearls
Treatments
Diagnosis and management of sodium disorders: hyponatremia and hypernatremia, American Family Physician
Hypernatremia, Renal & Urology News
Hypernatremia, StatPearls
Scientific studies and clinical trials
Hypernatremia: correction rate and hemodialysis, Case Reports in Medicine