Will Drinking Water Help Hyponatremia? The Dangers of Self-Medication

October 27, 2025 •

4 min read

Up to 20% of hospitalized patients have hyponatremia, a condition of low blood sodium. It is a dangerous misconception that will drinking water help hyponatremia?; in fact, drinking excessive water is often a cause of this life-threatening electrolyte imbalance and can worsen the condition significantly.

Quick Summary

Hyponatremia is a serious electrolyte disorder involving dangerously low blood sodium levels. The condition requires specific medical interventions, such as fluid restriction or saline solutions, rather than increased water intake, which can exacerbate the problem.

Key Points

Excess Water Is a Risk Factor: Drinking excessive plain water is a direct cause of dilutional hyponatremia, as it overwhelms the kidneys' ability to excrete water and maintain a healthy sodium balance.
Seek Medical Attention: Severe hyponatremia with acute neurological symptoms is a medical emergency requiring expert diagnosis and controlled treatment in a hospital setting.
Treatment Is Multifaceted: Corrective measures depend on the cause and severity, often involving fluid restriction, saline administration, or medications rather than more water.
Don't Self-Medicate: Attempting to treat hyponatremia by drinking more water is the wrong response and can dangerously exacerbate the condition, potentially causing severe neurological damage or death.
Understand the Cause: The appropriate treatment for hyponatremia is determined by the underlying cause, and addressing this root issue is paramount for effective management.
Athletes Need Electrolytes: Individuals engaged in long-duration exercise should consume sports drinks or salty foods to replace electrolytes lost through sweat, balancing fluid intake with sodium replenishment.
Fluid Restriction May Be Necessary: In cases of euvolemic or hypervolemic hyponatremia, restricting total fluid intake is a standard part of treatment to allow the body's sodium levels to normalize.

What Is Hyponatremia?

Hyponatremia is the medical term for low blood sodium, defined as a serum sodium concentration below 135 mEq/L. Sodium is a critical electrolyte that regulates fluid balance, nerve function, and muscle contractions. An imbalance can cause water to move into the body's cells, causing them to swell. This swelling can be particularly dangerous for brain cells, leading to severe neurological symptoms. The condition's severity depends on how low the sodium level drops and how quickly it happens. A slow, gradual drop may cause only mild symptoms, while a rapid decrease can lead to a medical emergency.

The Diverse Causes of Hyponatremia

Hyponatremia is rarely caused by drinking a normal amount of water but rather by a complex interplay of fluid intake and retention. Causes are broadly categorized by the body's fluid volume:

Hypovolemic Hyponatremia: Occurs when the body loses both water and sodium, but more sodium is lost. This can be caused by severe vomiting or diarrhea, extensive burns, or diuretic use.
Hypervolemic Hyponatremia: Involves an increase in both water and sodium, but the increase in water is disproportionately larger. This is commonly seen in patients with conditions like congestive heart failure, liver cirrhosis, and kidney disease.
Euvolemic Hyponatremia: Total body water increases while total body sodium remains stable. The most common cause is the syndrome of inappropriate antidiuretic hormone secretion (SIADH), which causes the body to retain excess water. This can also be caused by excessive intake of water (psychogenic polydipsia) or certain medications.

Why Drinking More Water Is the Wrong Solution

For most types of hyponatremia, especially those caused by water intoxication or retention (dilutional hyponatremia), increasing water intake is precisely the wrong course of action. The core problem is not a lack of hydration but rather an imbalance where there is too much water relative to sodium. Flooding the body with more water further dilutes the already low sodium concentration, worsening the condition and increasing the risk of serious complications like brain swelling, seizures, and coma.

Signs and Symptoms to Watch For

Symptoms of hyponatremia range from mild to life-threatening and can develop gradually or suddenly. Mild symptoms include:

Nausea and vomiting
Headache
Fatigue and drowsiness
Muscle weakness, cramps, or spasms

In more severe cases, symptoms become neurological and include:

Confusion, restlessness, and irritability
Seizures
Coma

Proper Treatment Strategies for Hyponatremia

Because the causes are so varied, treatment must be tailored to the specific type and severity of hyponatremia under medical supervision. Self-treatment, especially with more water, is strongly discouraged due to the risk of dangerous overcorrection.

Treatment Approaches by Type


Type of Hyponatremia	Cause	Standard Treatment	Additional Considerations
Hypovolemic	Significant fluid loss (vomiting, diarrhea, diuretics) with greater sodium loss	Intravenous (IV) fluids with a saline solution (isotonic) to replenish both water and sodium.	Treat underlying cause of fluid loss.
Euvolemic	Excess water retention (e.g., SIADH, excessive water intake)	Fluid restriction is often the first-line treatment, limiting daily fluid intake (water, coffee, tea, juices) to a set amount.	Medications like vaptans may be used in severe cases, along with addressing the root cause.
Hypervolemic	Total body fluid overload (e.g., heart failure, liver cirrhosis)	Fluid and sodium restriction combined with diuretics to increase fluid excretion.	Treating the underlying organ disease is critical.
Severe Acute	Rapid drop in sodium levels leading to severe neurological symptoms	Requires hospitalization for careful monitoring and treatment with hypertonic saline (3% NaCl) via IV infusion to raise sodium levels slowly.	Correcting too quickly can lead to permanent brain damage (Osmotic Demyelination Syndrome).

The Danger of Overcorrection

Osmotic demyelination syndrome (ODS) is a severe neurological complication that can occur if chronic hyponatremia is corrected too rapidly. When sodium levels rise too quickly, it can cause nerve cells in the brain to shrink and become damaged, leading to permanent neurological issues, paralysis, or death. Medical guidelines emphasize slow, controlled correction rates, especially in chronic cases, to prevent this outcome.

Prevention and Best Practices

Preventing hyponatremia, particularly for at-risk individuals, involves conscious hydration and electrolyte management.

Balance water with electrolytes: During high-intensity, long-duration exercise, it is crucial to consume sports drinks containing electrolytes or salty snacks alongside plain water to replace lost sodium.
Use thirst as a guide: Unless advised otherwise by a doctor, listening to your body's thirst signals is generally the best indicator for fluid intake. Urine color can also be a helpful cue; pale yellow urine indicates adequate hydration.
Mindful fluid intake: Be aware of total fluid intake and its sodium content, especially if on fluid restriction for a medical condition or prone to excessive drinking. Consuming fluids like broths or salty juices can help restore sodium levels, while low-sodium fluids like plain water should be limited.

Conclusion

The question of will drinking water help hyponatremia is fundamentally misguided. For a condition defined by an excess of water relative to sodium, adding more water only worsens the underlying issue, with potentially fatal consequences. The correct approach is always to seek medical diagnosis to determine the specific type of hyponatremia and its root cause. Only with proper medical guidance can a safe and effective treatment plan, which may involve fluid restriction or sodium replacement, be implemented. Self-treating by drinking more water is a dangerous shortcut that puts one at severe risk.

For additional information and professional medical advice on hyponatremia, please consult the Mayo Clinic's guide on the condition.

Frequently Asked Questions

Hyponatremia is a condition where the level of sodium in the blood is abnormally low, below 135 mEq/L. Symptoms can range from mild (nausea, headache, fatigue) to severe (confusion, seizures, coma) and depend on the rate and extent of the sodium drop.

Drinking more water is dangerous because it further dilutes the already low concentration of sodium in the blood, which can worsen symptoms and increase the risk of severe complications, including brain swelling.

Treatment for hyponatremia depends on the underlying cause. For some cases, it involves fluid restriction. For others, it requires intravenously administered saline solutions to raise sodium levels slowly. The underlying condition causing the imbalance must also be addressed.

Yes. Athletes, especially those in endurance events like marathons, are at risk of dilutional hyponatremia if they sweat out sodium but only replenish fluids with plain water. Sports drinks containing electrolytes are recommended for strenuous activities lasting more than an hour.

Mild, asymptomatic hyponatremia may be managed with fluid restriction or adjusting medications. Severe, symptomatic hyponatremia is a medical emergency that requires hospitalization for controlled intravenous administration of hypertonic saline to carefully raise sodium levels and prevent life-threatening complications.

Correcting hyponatremia too rapidly can cause osmotic demyelination syndrome (ODS), a condition where nerve cells in the brain are damaged from shrinking. This can lead to permanent neurological damage.

You should seek emergency medical care for anyone with serious symptoms like confusion, seizures, or lost consciousness. If you are at risk and experience persistent nausea, headaches, or muscle cramps, contact your healthcare provider.