Should you drink water with low sodium? A Guide to Healthy Hydration

January 2, 2026 •

4 min read

According to the National Kidney Foundation, low levels of sodium in the blood, known as hyponatremia, are most often caused by fluid imbalance rather than insufficient dietary sodium. Understanding this is key to knowing if you should drink water with low sodium and what it means for your body.

Quick Summary

Deciding whether to drink low sodium water depends on your individual health needs. It can be beneficial for managing certain conditions but may pose risks for others, particularly athletes who sweat heavily. The right choice is about balancing your overall fluid and sodium intake.

Key Points

Low Sodium Water Benefits: Can help manage conditions like hypertension and kidney disease by reducing overall sodium intake.
Hyponatremia Risk: Endurance athletes and those exercising intensely risk dangerously low blood sodium (hyponatremia) if they only drink plain, low sodium water and don't replace lost electrolytes.
Diet Over Water: For most people, the sodium in drinking water is negligible compared to the high levels found in processed foods.
Listen to Your Body: Drink water based on thirst, especially during exercise, and don't force excessive fluid intake.
Personalized Approach: Consult a healthcare provider for personalized advice on hydration, especially if you are on a restricted diet or are a high-level athlete.
Check Your Sources: If concerned, check water quality reports for tap water or labels for bottled water; some use reverse osmosis to remove sodium.
Balance is Key: Maintaining a proper balance of fluid and electrolytes is crucial for optimal bodily function for everyone, regardless of activity level.

The Crucial Role of Sodium in Your Body

Sodium, an essential electrolyte, is fundamental to many critical bodily functions. It plays a pivotal role in maintaining the balance of fluids, controlling blood pressure, and enabling the proper function of nerves and muscles. The average American consumes significantly more sodium than required, primarily through processed foods, not water. While your body is excellent at regulating sodium levels, imbalances can lead to health issues. For the vast majority of people, the minimal amount of sodium in tap water is insignificant to their overall intake. The primary focus for sodium management should almost always be on dietary sources.

Potential Benefits of Low Sodium Water

For certain groups, intentionally consuming low sodium water can be a beneficial part of a broader health strategy. It is particularly relevant for those managing specific medical conditions.

Supporting Heart and Kidney Health

High sodium intake is a well-established risk factor for high blood pressure (hypertension) and cardiovascular disease. Individuals with these conditions are often placed on sodium-restricted diets. Choosing water with a lower sodium content can help minimize their total daily intake, easing the burden on the heart and kidneys. For people with kidney disease, who may have difficulty excreting excess fluid, low sodium water can assist in managing fluid balance.

Reducing Water Retention

Excessive sodium can cause the body to retain water, leading to bloating and swelling (edema). By opting for lower sodium hydration, some individuals may find it helps reduce fluid retention and promote a leaner appearance.

The Risks of Low Sodium Water for Athletes

While low sodium water might sound universally healthy, it can be detrimental to performance and safety for athletes and others engaged in intense, prolonged exercise. When you sweat, you lose both water and electrolytes, including sodium.

The Danger of Hyponatremia

For endurance athletes, or those exercising heavily for more than four hours, drinking excessive amounts of plain, low sodium water without replacing lost electrolytes is a significant risk factor for exercise-associated hyponatremia (EAH). This dangerous condition occurs when blood sodium levels become diluted. Symptoms range from mild (nausea, fatigue, headache) to severe (seizures, coma, and even death). The Korey Stringer Institute notes that excessive drinking, particularly hypotonic (low sodium) fluids, can cause this imbalance. Balancing fluid and sodium intake is critical for performance and safety during long bouts of intense exercise. For more detailed information on this condition, see the guide on hyponatremia from the Cleveland Clinic.

Comparison: Low Sodium Water vs. Regular Water


Feature	Low Sodium Water	Regular/Tap Water	Considerations
Sodium Content	Typically less than 20 mg/L	Varies widely, but generally higher than low-sodium water. Tap water in North America is often 18–41 mg/L.	Most people's water intake contributes a small fraction of total sodium intake.
Target Consumer	Individuals on strict sodium-restricted diets, those with hypertension, or kidney issues.	General population for everyday hydration.	The need for low sodium water is specific, not universal.
Risk for Athletes	Potential risk of hyponatremia if consumed excessively during prolonged, intense exercise without proper electrolyte replacement.	Less risk of hyponatremia than pure water if adequate electrolytes are also consumed via sports drinks or diet.	Athletes must balance water and electrolyte intake based on sweat loss.
Taste	Often described as having a cleaner, purer taste due to fewer dissolved minerals.	Can vary based on mineral composition, including sodium, chloride, and total dissolved solids (TDS).	Taste is a personal preference.
Cost	Typically higher, as it's often a specialized bottled product.	Lower, as it's often from a public utility or well source.	Cost is a significant factor in long-term consumption.

Making the Right Hydration Choice

Choosing the right water for your needs requires a personalized approach. Consider your overall health, diet, and activity level. For most healthy adults, the sodium content in tap water is negligible and not a concern. However, if you fall into a specific category, a more deliberate choice may be warranted.

Who should consider low sodium water?

Individuals on a severely sodium-restricted diet: Those required by a doctor to limit sodium intake to 500 mg or less per day should be mindful of all sources, including water.
People with hypertension or kidney disease: These conditions make managing fluid and sodium balance more challenging.
Those seeking a different taste: Some prefer the taste of low-mineral water.

Who should be cautious with low sodium water?

Endurance and high-intensity athletes: During long events, it's crucial to replenish electrolytes lost in sweat. Drinking only low sodium water can lead to hyponatremia. Sports drinks or electrolyte supplements are better options.
People with regular, non-intensive activity: For standard exercise, drinking to thirst and maintaining a balanced diet is typically sufficient without needing to specifically alter water's sodium content.

Final Recommendations

Ultimately, the decision to drink low sodium water is not a one-size-fits-all answer. For the general population, the impact is minimal. The best approach to hydration is to listen to your body and consult with a healthcare professional or registered dietitian for personalized advice, especially if you have an underlying medical condition or are an athlete. Your dietary choices, particularly regarding processed foods, will have a far greater impact on your sodium intake than the water you drink.

Conclusion

While low sodium water offers clear benefits for specific populations like those with hypertension or on strict diets, it is not a magical solution for everyone. The risks for endurance athletes, who need to actively replenish lost electrolytes, highlight the need for a balanced and informed approach to hydration. Your overall dietary patterns and activity levels are far more significant than the sodium content of your drinking water for most healthy adults. By considering your individual needs and consulting experts, you can make the best hydration choices for your health and performance. Choosing a water and hydration strategy that complements your lifestyle is the ultimate path to well-being.

Frequently Asked Questions

For most healthy people, no. The amount of sodium in drinking water is generally very small and not a significant source of your daily intake. However, for endurance athletes or people exercising intensely for prolonged periods, drinking too much low-sodium water without replacing electrolytes can be dangerous and lead to hyponatremia.

People who are on a doctor-recommended, severely sodium-restricted diet, often due to conditions like hypertension or kidney disease, may benefit from choosing water with low sodium to help manage their overall intake.

Drinking low sodium water alone is unlikely to cause hyponatremia in healthy individuals. The risk primarily arises in scenarios where someone loses a large amount of sodium through sweat during intense exercise and then over-hydrates with plain water, diluting their blood's sodium concentration.

For bottled water, check the nutrition label for the sodium content. If you have tap water, you can check your local water quality report or have a sample tested by a certified lab. Water with less than 20 mg/L is generally considered very low in sodium.

The Institute of Medicine (IOM) suggests aiming for about 1,500 mg per day for most adults. The upper tolerable intake level is 2,300 mg per day. For most, dietary choices have a much greater impact on this number than water.

No, endurance athletes should not exclusively drink low sodium water during long or intense exercise, as this can increase their risk of hyponatremia. They should use sports drinks or other electrolyte-replacing fluids to replenish lost sodium and other minerals.

Yes, water softening systems use an ion exchange process that replaces hard minerals like calcium and magnesium with sodium. This can add a significant amount of sodium to your water, which is a concern for those on sodium-restricted diets.