What fluid is best for low sodium? A Comprehensive Guide to Hyponatremia

January 7, 2026 •

4 min read

According to the Mayo Clinic, hyponatremia is a condition where blood sodium is abnormally low and can lead to serious health complications like brain swelling and coma if severe. Determining what fluid is best for low sodium is critical for safe management and depends on the underlying cause and severity of the condition.

Quick Summary

For mild low sodium, electrolyte-rich options like sports drinks, oral rehydration solutions, and broths are often recommended, while excessive plain water should be avoided. Medical supervision is required for diagnosis and treatment, as approaches vary based on the underlying cause and severity of hyponatremia.

Key Points

Electrolyte Solutions: Sports drinks and oral rehydration solutions are effective fluids for replenishing sodium and other key electrolytes lost during intense exercise or illness.
Salty Broths: Naturally high in sodium, broths and soups are a comforting and appropriate fluid choice for mild low sodium cases, especially during recovery from illness.
Restrict Plain Water: For individuals with hyponatremia, excessive intake of plain water can worsen the condition by further diluting blood sodium levels and should be limited.
Medical Emergency: Severe symptoms of hyponatremia, such as confusion or seizures, require immediate medical attention and hospital treatment with carefully administered IV fluids.
Underlying Cause: Proper treatment for low sodium must address the root cause, whether it's excessive fluid intake, medication, or a chronic health condition.
Professional Guidance: Always consult a healthcare provider for diagnosis and treatment of hyponatremia to avoid dangerous health complications from improper management.

Understanding Hyponatremia: What Causes Low Sodium?

Hyponatremia is a common electrolyte imbalance where the concentration of sodium in the blood falls below the normal range, typically considered less than 135 mEq/L. Sodium is a vital electrolyte that helps regulate the balance of water inside and outside of your cells. When blood sodium is low, water moves into your cells, causing them to swell. This can be especially dangerous for brain cells, which have limited room to expand within the skull.

There are many potential causes of hyponatremia, ranging from medical conditions to lifestyle factors. Some of the most common reasons include:

Excessive water intake: Drinking too much water, especially during endurance sports, can overwhelm the kidneys' ability to excrete it, diluting the sodium in the blood.
Certain medications: Thiazide diuretics (water pills), some antidepressants, and pain medications can interfere with the body's sodium regulation.
Chronic health conditions: Heart failure, kidney disease, and cirrhosis of the liver can cause fluid retention, leading to diluted sodium levels.
Vomiting and diarrhea: Severe or chronic episodes can lead to the loss of both sodium and fluids.
Hormonal imbalances: Conditions like Addison's disease or low thyroid hormone levels can affect the balance of sodium and water.

The Best Fluids for Mild Cases of Low Sodium

For mild, chronic low sodium, a healthcare provider might recommend dietary adjustments. In these instances, focusing on fluids that contain adequate sodium is key. It is essential to consult a doctor before self-treating, as the best approach depends on the underlying cause.

Electrolyte-Rich and Rehydration Solutions

These are often the first line of defense for non-severe cases, especially when the cause is related to exercise or dehydration from illness.

Sports Drinks: Beverages like Gatorade or Powerade contain a balance of sodium, potassium, and carbohydrates to help restore electrolyte levels.
Oral Rehydration Solutions (ORS): Products like Pedialyte are specifically formulated to replace fluids and electrolytes lost due to vomiting or diarrhea.

Nutrient-Dense Options: Broths and Juices

Broths and Soups: Chicken, beef, or vegetable broths are naturally high in sodium and can be a comforting and effective way to increase sodium levels.
Tomato or Vegetable Juice: Standard versions (not low-sodium) can be a good source of sodium and other nutrients.

Homemade Electrolyte Solutions

For a DIY approach, you can create a simple electrolyte drink. For instance, mixing water, a pinch of salt, and a splash of fruit juice can provide a quick sodium boost. However, homemade options should be used with caution and after consulting a medical professional to ensure appropriate ratios.

The Dangers of Excess Water and When to Restrict Fluids

While proper hydration is important, drinking excessive amounts of plain water can be detrimental when you have low sodium. This dilutes the existing sodium in your blood, exacerbating the problem. In many cases of mild to moderate hyponatremia, a doctor may recommend fluid restriction to help normalize blood sodium concentration. Fluids to limit or avoid include plain water, tea, and coffee, which are mostly water and can worsen the dilution effect.

Medical Intervention for Severe Cases

Severe hyponatremia is a medical emergency that requires aggressive and carefully monitored treatment. Options include:

Intravenous (IV) Sodium Solution: In a hospital setting, a healthcare professional may administer an IV sodium solution to slowly raise blood sodium levels. Rapid correction is dangerous and can cause severe, permanent brain damage.
Medications: Certain medications may be prescribed to manage severe symptoms or address the underlying cause.

Comparing Fluids for Low Sodium


Fluid Type	Sodium Content	Other Electrolytes	Best For	Considerations
Broths/Soups	High	Potassium, varied	Replenishing sodium, especially during illness	High in sodium, can be very salty. Flavored options may contain MSG.
Sports Drinks	Moderate	Potassium	Endurance athletes, post-illness recovery	High sugar content in some varieties. Read labels for sodium levels.
Oral Rehydration Solutions	High	Potassium, Chloride	Recovery from diarrhea/vomiting	Specifically formulated for rehydration. Less palatable than sports drinks.
Plain Water	Very Low	None	General hydration for those with normal sodium levels	Should be limited or avoided in diagnosed low sodium cases to prevent further dilution.
Tomato/Vegetable Juice	Moderate	Potassium	Mild cases, dietary adjustments	Choose traditional, not low-sodium versions for benefit.

When to Seek Medical Attention

While mild symptoms like fatigue or nausea can indicate low sodium, severe symptoms require immediate medical care. You should seek emergency treatment if you or someone you know experiences any of the following:

Severe confusion or altered mental status
Seizures or convulsions
Loss of consciousness or coma
Difficulty waking up
Severe headaches, especially when accompanied by vomiting

For anyone with a known risk factor, such as kidney disease or heart failure, or taking certain medications, regular monitoring and professional guidance are essential. Your healthcare provider can determine the best course of action based on a thorough medical evaluation.

Conclusion: Prioritizing Expert Guidance for Low Sodium

When it comes to the question of what fluid is best for low sodium, there is no single answer. The correct choice is highly dependent on the severity and underlying cause of hyponatremia. For mild cases, electrolyte-rich options like broths and sports drinks can be helpful, while fluids that are mostly plain water should be restricted. However, severe or symptomatic hyponatremia is a medical emergency and should never be self-treated. Always consult a healthcare professional for an accurate diagnosis and a personalized treatment plan, as improper correction of sodium levels can lead to serious and irreversible complications. For more information on hyponatremia, visit the Cleveland Clinic website.

Frequently Asked Questions

Yes, drinking excessive amounts of plain water can cause low sodium, or dilutional hyponatremia. It can overwhelm the kidneys' ability to excrete water, diluting the sodium in the blood.

Early signs of low sodium often include nausea, headache, fatigue, and muscle cramps or weakness. As the condition worsens, more severe symptoms can develop.

Yes, sports drinks can be a good fluid for low sodium, particularly if it's related to intense exercise. They contain a balanced mix of sodium and other electrolytes to help restore levels.

Coconut water is naturally hydrating and rich in potassium, but its sodium content varies. Some brands have added sodium for better electrolyte balance, while others may not provide enough to address low sodium levels effectively.

You should limit or avoid fluids that are mostly water and contain little or no sodium. This includes plain water, tea, and coffee, which can further dilute blood sodium levels.

You should see a doctor if you suspect you have low sodium, especially if you have an underlying health condition that increases your risk. Seek emergency care for severe symptoms like confusion, seizures, or loss of consciousness.

Yes, broths and soups are naturally high in sodium and can be a very effective and palatable way to increase sodium intake for those with mild hyponatremia.

Yes, some medications can cause low sodium levels. Diuretics (water pills), some antidepressants, and certain pain medicines can interfere with the hormonal and kidney processes that regulate sodium.