When the concentration of sodium in your bloodstream falls below the normal range, typically defined as less than 135 milliequivalents per liter (mEq/L), the condition is medically known as hyponatremia. Sodium is an electrolyte that plays a regulatory role in the body’s water balance. It helps control the amount of fluid both inside and outside your cells, which is why a change in its concentration can have widespread effects. Maintaining the correct sodium level is also important for supporting proper nerve impulse transmission and muscle contractions, including those of the heart.
Identifying the Causes of Low Sodium
Low sodium levels are often a result of an imbalance between sodium and water, rather than simply not consuming enough salt. A common cause is drinking excessive amounts of water, which dilutes the sodium already present in the bloodstream. This dilution effect can overwhelm the kidneys’ ability to excrete the excess fluid, lowering the concentration of sodium.
Prolonged, intense physical activity, such as marathon running, can also lead to low sodium if lost electrolytes are replaced only with plain water. Sweating causes the body to lose both water and sodium, and failing to replenish the sodium can result in a deficit. Certain medications, particularly diuretics often prescribed for high blood pressure or heart conditions, can increase the excretion of sodium by the kidneys, contributing to hyponatremia.
Underlying health issues, including heart failure, advanced kidney disease, or liver disease, can impair the body’s ability to manage fluid, often causing water retention that dilutes the blood sodium. Hormonal imbalances, such as the Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH), cause the body to retain too much water. Severe and chronic episodes of vomiting or diarrhea also deplete the body of both fluid and electrolytes, including sodium, which can lead to a low concentration.
Dietary Choices to Raise Sodium Levels
Increasing your dietary intake of sodium should be done gradually and in consultation with a healthcare professional, especially since rapid correction can be dangerous. For people with mild hyponatremia, incorporating specific sodium-rich foods can help to restore balance. These foods provide the necessary electrolytes to counter the deficit or dilution.
Sodium-Rich Food Sources
- Broths and soups are excellent, easily digestible sources of sodium, with many canned varieties containing high levels per serving.
- Electrolyte beverages or sports drinks designed to replace minerals lost through sweat can also be helpful, as they are formulated to contain sodium and other electrolytes.
- Salted snack foods offer a convenient and measurable way to increase sodium intake, such as pretzels, crackers, and dry-roasted nuts or seeds.
- Canned goods, such as beans, vegetables, or seafood like tuna or shrimp, are typically preserved in a high-sodium brine.
- Fermented foods, including pickles, sauerkraut, and miso paste, contain substantial amounts of sodium due to their preparation and preservation.
- Condiments, including soy sauce, tomato sauce, and certain cheeses like cottage cheese, also have naturally high sodium content due to their processing or preparation methods.
When opting for any of these foods, it is important to read nutrition labels and choose options that are not labeled “low-sodium,” as the goal is to increase the mineral’s concentration.
Managing Fluid Intake
Given that hyponatremia is frequently caused by an excess of water relative to sodium, managing fluid intake is often a more important strategy than simply adding salt to food. For cases where the body has retained too much water, a doctor may recommend fluid restriction, limiting total daily intake to a specific volume. This strategy allows the kidneys to gradually excrete the excess water, thereby concentrating the sodium level back to normal.
The type of fluid consumed is also an important consideration. Drinking large volumes of plain water can worsen the dilutional effect, especially if the underlying issue is the body’s impaired ability to excrete water. Instead, balancing plain water intake with fluids that contain electrolytes can help maintain the correct ratio of sodium to water. This is particularly relevant during periods of heavy sweating or prolonged exertion.
Fluid management plans are highly individualized and depend on the specific cause of the low sodium level. For instance, in hypovolemic hyponatremia, where both water and sodium have been lost, the treatment involves replacing both. However, in euvolemic or hypervolemic states, where the body volume is normal or high, restricting fluid is the primary approach to restore the electrolyte balance.
Recognizing When Professional Help Is Needed
While mild, asymptomatic low sodium may be managed with dietary adjustments, severe hyponatremia can be a medical emergency. The symptoms of low sodium levels can vary from mild to life-threatening, depending on how quickly the concentration drops. Early, milder symptoms include fatigue, headache, nausea, and muscle cramps or weakness.
If the condition progresses, more severe symptoms that indicate a need for immediate medical attention can develop. These warning signs include severe confusion, disorientation, or altered mental status, which suggest an effect on the brain. Seizures, persistent or severe vomiting, or a sudden loss of consciousness are also signs of dangerous hyponatremia.
Individuals who have a chronic medical condition, such as heart failure, kidney disease, or a disorder of the adrenal gland, should always consult their doctor before making significant changes to their fluid or sodium intake. Similarly, if low sodium is suspected to be a side effect of a prescription medication, a physician must be involved to safely adjust the dosage or switch to an alternative treatment. Self-treating severe symptoms or attempting to rapidly correct the sodium level without medical guidance can lead to serious complications.