The concept of drinking “salt water” for hydration refers to the strategic use of a dilute electrolyte solution, often termed an Oral Rehydration Solution (ORS). This solution is composed of water, a small amount of salt (sodium chloride), and typically a sugar source. Plain water is sufficient for normal hydration, but in specific physiological states involving significant fluid loss or electrolyte imbalance, the addition of sodium and glucose is necessary to facilitate water absorption in the small intestine. This practice is a highly situational intervention, not a daily habit, and must be approached with caution due to the body’s strict requirements for sodium balance.
Contexts for Strategic Hydration and Electrolyte Replacement
The intentional intake of sodium via water is beneficial or necessary when the body is rapidly losing both fluid and electrolytes. This situation most often occurs during high-intensity or prolonged physical activity, particularly in endurance sports. Athletes lose substantial sodium through sweat, sometimes up to 700 milligrams per hour, which plain water cannot replace. Consuming water without sodium in these conditions can lead to exercise-associated hyponatremia, a state of abnormally low blood sodium concentration.
Sodium-containing fluids are also appropriate during acute illness that causes rapid fluid loss, such as severe vomiting or persistent, watery diarrhea. These conditions strip the body of necessary electrolytes like sodium, chloride, and potassium, leading to dehydration and electrolyte imbalance. An ORS solution is designed to maintain the osmotic balance, helping the body absorb fluid and replace the minerals lost through the gastrointestinal tract.
Certain dietary contexts also create conditions where increased sodium intake is beneficial to maintain fluid balance. Individuals following very low-carbohydrate plans, such as the ketogenic diet, often experience a rapid loss of fluid and sodium. The reduction in carbohydrate intake lowers insulin levels, which signals the kidneys to excrete more sodium through urine. Increasing sodium intake in these specific contexts can help mitigate common side effects like headache, dizziness, and fatigue, collectively known as the “keto flu”.
Guidelines for Safe Preparation and Concentration
Safe preparation of a sodium-containing hydration solution requires precise measurement to ensure the concentration is therapeutic and not harmful. A common preparation involves mixing one liter of clean water with about a half-teaspoon of table salt and six to eight level teaspoons of sugar. The sugar, typically glucose, is included because it helps the small intestine absorb the sodium and water through a specific transport mechanism.
Using household measuring spoons requires care, as a slightly heaped spoon can significantly alter the sodium concentration, making the solution hypertonic and potentially dangerous. The water used should be clean and safe; boiling and cooling tap water is recommended if the quality is uncertain. While plain table salt (sodium chloride) is effective, some recipes suggest adding a small amount of potassium chloride or baking soda to provide additional electrolytes and balance the formulation.
The balance of sodium, glucose, and water creates an optimal osmotic pressure for rehydration. The solution should be consumed in small, frequent sips, especially in cases of vomiting, to maximize absorption and prevent stomach upset. Any prepared solution should be discarded after 24 hours if kept at room temperature to prevent contamination.
Risks and Situations Requiring Avoidance
Improperly concentrated or excessive consumption of salt water poses significant health risks, primarily the development of hypernatremia, an abnormally high concentration of sodium in the blood. When the sodium level rises too high, it draws water out of the body’s cells, causing them to shrink. This fluid imbalance can be caused by consuming too much sodium or not drinking enough plain water to dilute the sodium concentration.
Symptoms of over-consumption can include extreme thirst, confusion, restlessness, and lethargy, requiring immediate medical attention. In severe cases, hypernatremia can lead to seizures and coma. Chronic excessive sodium intake can also contribute to high blood pressure by increasing the volume of water in the bloodstream, putting added strain on the heart and blood vessels.
Individuals with certain pre-existing medical conditions should avoid strategic salt water intake unless specifically directed by a healthcare professional. People with hypertension, kidney disease, or congestive heart failure already struggle to manage fluid and sodium balance. Since the kidneys are responsible for regulating sodium levels, impaired kidney function can make it difficult for the body to excrete excess salt, increasing the risk of hypernatremia and fluid overload.