What Treats Low Sodium and Its Underlying Causes?

October 27, 2025 •

4 min read

Hyponatremia, the medical term for low sodium, affects up to 20% of hospitalized patients and can arise from various factors, including underlying medical issues or excessive fluid intake. Understanding what treats low sodium is crucial, as the correct approach depends heavily on the root cause and severity of the condition.

Quick Summary

Treatment for low blood sodium, or hyponatremia, varies based on its cause, severity, and duration. It may involve dietary modifications, fluid restriction, adjusting medications, or, in severe cases, intravenous fluids and hospitalization. Identifying and addressing the underlying issue is key for effective management and recovery.

Key Points

Cause-Specific Treatment: The correct treatment for low sodium (hyponatremia) is highly dependent on identifying and addressing the specific underlying cause.
Severity Determines Approach: Treatment strategies range from simple dietary changes for mild cases to immediate medical intervention with intravenous fluids for severe, acute hyponatremia.
Fluid Management is Key: For many patients, managing fluid intake is a primary treatment component, whether through restriction in cases of excess fluid or careful rehydration in cases of fluid loss.
Medications Target Hormones: In conditions like SIADH, medications such as vaptans or oral urea can be used to regulate water excretion by affecting antidiuretic hormone (ADH).
Dietary Changes for Mild Cases: For mild hyponatremia, a doctor might recommend increasing dietary sodium through salty foods or supplements, but this must be medically supervised.
Gradual Correction is Essential: Rapidly correcting sodium levels can be dangerous, potentially causing brain damage; therefore, careful and gradual correction is the standard of care.
Medical Supervision is Necessary: Self-treating low sodium is risky. All management and treatment plans, especially for severe or chronic hyponatremia, should be guided by a healthcare professional.

Understanding Low Sodium (Hyponatremia)

Hyponatremia occurs when the sodium concentration in the blood falls below 135 mEq/L, disrupting the body's delicate electrolyte and fluid balance. Sodium is vital for nerve function, muscle contraction, and blood pressure regulation. A deficit can lead to symptoms ranging from mild headaches and fatigue to severe neurological issues like confusion, seizures, and even coma. The treatment strategy is not one-size-fits-all, requiring a medical professional to first diagnose the underlying cause and determine if the condition is acute (rapid onset) or chronic (gradual onset).

The Diverse Causes of Hyponatremia

Before a treatment plan can be established, doctors must pinpoint the cause of the low sodium levels. Some common culprits include:

Certain medications: Water pills (diuretics), antidepressants, and pain relievers can interfere with the body's sodium and water regulation.
Medical conditions: Heart, liver, and kidney problems, such as congestive heart failure and cirrhosis, can cause fluid accumulation that dilutes sodium.
Hormonal changes: Adrenal gland insufficiency (Addison's disease) and hypothyroidism can disrupt hormone levels that help maintain sodium balance.
Excessive fluid intake: Drinking too much water, especially during intense physical activity like marathons, can overwhelm the kidneys' ability to excrete water.
Syndrome of inappropriate antidiuretic hormone (SIADH): This condition causes the body to retain too much water.

Medical Treatments for Low Sodium

In a clinical setting, medical management is tailored to the severity and cause of hyponatremia. Mild cases may only need minor adjustments, while severe, symptomatic cases require immediate and careful intervention.

Hospital-Based Treatments

Intravenous (IV) Fluids: For severe, acute hyponatremia, a healthcare professional may administer a slow IV drip of a saline solution to gradually raise blood sodium levels. This must be done with extreme caution, as correcting sodium too rapidly can cause dangerous complications like osmotic demyelination syndrome.
Medications: Specific drugs, such as vasopressin receptor antagonists (e.g., tolvaptan, conivaptan) or loop diuretics (e.g., furosemide), may be prescribed. These medications help manage fluid balance or increase the excretion of excess water. In cases related to SIADH, oral urea may also be used to promote water excretion.
Addressing the Underlying Condition: The primary focus is often on treating the root cause, whether it's adjusting medication dosages, managing heart or kidney failure, or treating hormonal imbalances.

Home-Based Management (for mild or chronic cases)

Fluid Restriction: For certain types of hyponatremia, particularly those related to excess fluid, doctors may recommend temporarily limiting fluid intake.
Dietary Adjustments: Increasing dietary sodium through specific foods or adding more salt to meals can be effective for mild cases, particularly when paired with loop diuretics. High-sodium foods include cured meats, salted nuts, and canned products.
Salty Snacks and Drinks: In some situations, salty foods or electrolyte-rich sports drinks can help replenish sodium lost through sweating or other fluid loss.

Comparing Hyponatremia Treatment Methods


Treatment Method	Best for	Key Considerations	Risks
Intravenous (IV) Saline	Severe, symptomatic hyponatremia, or rapidly decreasing levels.	Requires hospitalization and close monitoring of blood sodium to avoid overcorrection.	Overly rapid correction can cause osmotic demyelination syndrome.
Fluid Restriction	Moderate, chronic hyponatremia, often with SIADH or over-hydration.	Non-adherence can be a challenge. Efficacy depends on the patient's individual renal capacity.	Can be insufficient for some patients and may not address underlying causes effectively.
Vaptan Medications (e.g., Tolvaptan)	Euvolemic and hypervolemic hyponatremia, including cases with SIADH or heart failure.	Requires initiation and re-initiation in a hospital setting and is not for long-term use due to liver risk.	Potential for severe liver injury and rapid sodium overcorrection.
Oral Urea	SIADH-related hyponatremia, as a second-line treatment option.	Considered effective and well-tolerated, and can be used long-term.	Contraindicated in certain conditions like cirrhosis and hypovolemia.
Increased Dietary Sodium	Mild hyponatremia, especially when associated with low dietary intake.	Requires doctor's approval, as increasing salt is not suitable for all patients, particularly those with certain kidney or heart issues.	Ineffective for severe cases and can exacerbate conditions like heart failure if not properly supervised.

A Note on Self-Management and Expert Advice

While some dietary strategies can be implemented at home, it is crucial to emphasize that any treatment for low sodium should be done under a doctor's supervision. The wrong treatment or rate of correction can have serious consequences. A medical professional will determine the appropriate course of action based on a thorough evaluation of the underlying cause, the severity of the condition, and the patient's overall health.

The Importance of Monitoring

Regular monitoring of blood sodium levels is a critical component of treatment. This helps ensure the chosen therapy is working effectively and prevents dangerous overcorrection. Patients with certain chronic conditions, like heart or kidney failure, will need consistent follow-up care to manage their electrolyte balance and overall health.

Conclusion

What treats low sodium is a complex question with a range of answers, from simple dietary adjustments to advanced medical interventions. The correct approach depends on the underlying cause, severity, and chronicity of hyponatremia, and must always be determined by a healthcare provider. Whether it's fluid restriction, specific medications, or IV solutions, the goal is to safely and gradually restore the body's sodium balance while addressing the root cause. For anyone experiencing symptoms, seeking immediate medical evaluation is the most important step to ensure a safe and effective treatment plan.

Frequently Asked Questions

The fastest way to increase sodium levels is through the intravenous (IV) administration of a sodium solution, which is reserved for severe, symptomatic cases and performed in a hospital setting under strict medical supervision.

Dietary adjustments can help manage mild, chronic low sodium levels, but they are not sufficient for moderate to severe cases. It is essential to consult a doctor, as the underlying cause and severity dictate the appropriate treatment.

Doctors treat severe low sodium by administering a slow, carefully monitored intravenous saline solution in a hospital. The goal is to raise blood sodium levels gradually to prevent neurological complications.

Foods naturally high in sodium include seafood and dairy products. Processed foods like cured meats, salted nuts, and canned goods also contain high amounts of sodium. Electrolyte-rich drinks can also be beneficial.

Correcting low sodium levels too quickly can lead to osmotic demyelination syndrome (ODS), a severe and potentially permanent form of brain damage.

In cases where low sodium is caused by excess body water (dilutional hyponatremia), fluid restriction helps reduce the amount of diluting fluid in the body, allowing sodium levels to rise.

Yes, excessive water intake, particularly during intense exercise or in individuals with conditions that impair water excretion, can dilute the blood's sodium content and lead to hyponatremia.