Why Am I Lacking in Salt? Understanding the Causes of Low Sodium

November 30, 2025 •

5 min read

According to the National Kidney Foundation, hyponatremia, the medical term for low blood sodium, is the most common electrolyte disorder. Understanding why you are lacking in salt is crucial because this condition, often linked to an imbalance of water and sodium, can arise from various medical and lifestyle factors, some of which may be serious.

Quick Summary

Low blood sodium, or hyponatremia, is caused by an imbalance between the body's water and sodium content, resulting from issues like excessive fluid intake, certain medications, or underlying diseases. Symptoms range from mild fatigue to severe neurological issues. A blood test is necessary for diagnosis, and treatment targets the underlying cause to restore a safe sodium balance.

Key Points

Fluid Overload: The most common reason for low sodium (hyponatremia) is having too much water in the body, which dilutes the blood, rather than a simple salt deficit.
Medical Causes: Underlying health conditions such as kidney disease, heart failure, and liver cirrhosis can disrupt the body's fluid balance, leading to hyponatremia.
Medication Impact: Many common drugs, including diuretics, some antidepressants, and pain medications, can interfere with hormonal and kidney processes that regulate sodium.
Symptom Spectrum: Symptoms range from mild and gradual (fatigue, headache, nausea) to severe and rapid-onset (confusion, seizures, coma), warranting immediate medical attention.
Avoid Rapid Correction: Self-treatment is dangerous, as a doctor must carefully monitor and correct sodium levels to avoid life-threatening side effects like brain damage from rapid correction.
High-Risk Activities: Endurance athletes who drink excessive plain water during exercise and lose sodium through sweat are particularly at risk for exertional hyponatremia.

What is Hyponatremia?

Sodium is a vital electrolyte, a mineral that carries an electric charge, and plays a crucial role in the body. Most of the body's sodium is found in the fluid surrounding your cells, and its primary functions include regulating fluid balance, controlling blood pressure, and ensuring proper nerve and muscle function. Hyponatremia is the term used when the sodium concentration in the blood is too low (below 135 mEq/L). This imbalance causes water to move into cells, making them swell. Brain cells are particularly sensitive to this swelling, which leads to many of the symptoms associated with the condition. The imbalance is often more about having too much water relative to sodium, rather than a lack of salt in the diet.

Common Causes of Low Sodium Levels

Several factors can contribute to low sodium levels. It is important to note that many cases are not simply due to a low-salt diet but rather complex physiological issues.

Excessive Fluid Intake

One of the most straightforward causes of hyponatremia is consuming too much water, which dilutes the sodium concentration in the blood. This is a common issue for endurance athletes who drink large volumes of plain water without replenishing electrolytes lost through sweat. A less common but severe form, known as "beer potomania," can affect people who consume excessive beer while eating a low-protein diet, as the solute load is insufficient for the kidneys to excrete free water.

Certain Medications

Prescription medications can significantly impact sodium balance. Some of the most common include:

Diuretics: Often called "water pills," these medications increase urine output and can cause excessive sodium excretion.
Antidepressants: Selective serotonin reuptake inhibitors (SSRIs) have been linked to hyponatremia, particularly in older adults.
Pain Medications: Certain pain relievers can interfere with sodium retention.
Chemotherapy Drugs: Some cancer treatments can cause sodium imbalances.

Medical Conditions

Various underlying health issues can disrupt the body's fluid and sodium regulation:

Kidney Disease: The kidneys are crucial for maintaining electrolyte balance. Conditions like acute or chronic kidney disease can impair their ability to excrete water, leading to dilution of sodium.
Heart Failure: This condition can cause the body to retain excess fluid, diluting sodium levels.
Liver Disease: Conditions like cirrhosis can lead to fluid accumulation and low sodium.
Hormonal Imbalances: Hormones from the adrenal glands (Addison's disease) and thyroid gland (hypothyroidism) can affect sodium levels. A more specific cause is the Syndrome of Inappropriate Antidiuretic Hormone (SIADH), where the body produces too much antidiuretic hormone, causing water retention.
Severe Vomiting or Diarrhea: Prolonged or severe fluid loss can cause dehydration and deplete sodium levels.

Symptoms to Watch For

Symptoms of hyponatremia can vary depending on its severity and speed of onset. Mild cases may be asymptomatic, while a rapid drop in sodium can cause severe, life-threatening symptoms.

Mild to Moderate Symptoms:

Nausea and vomiting
Headache
Fatigue, low energy, or drowsiness
Muscle weakness, cramps, or spasms
Restlessness and irritability
Confusion

Severe Symptoms:

Severe confusion or altered mental status
Seizures
Loss of consciousness
Coma
Brain swelling, which can be fatal if not treated immediately

Comparing Hyponatremia by Cause

Understanding the volume status is key to correctly diagnosing and treating hyponatremia. Low sodium is often categorized based on the patient's fluid volume—low (hypovolemic), normal (euvolemic), or high (hypervolemic).


Feature	Hypovolemic Hyponatremia	Euvolemic Hyponatremia	Hypervolemic Hyponatremia
Body Fluid Level	Decreased total body fluid and sodium, with sodium loss being greater.	Increased total body fluid, but total body sodium remains the same.	Increased total body fluid and sodium, with fluid gain being greater.
Common Causes	Severe vomiting, diarrhea, intense sweating, or diuretic use.	SIADH, hypothyroidism, or adrenal insufficiency.	Congestive heart failure, liver cirrhosis, or kidney disease.
Treatment Focus	Fluid resuscitation with isotonic saline to restore both fluid and sodium balance.	Fluid restriction to limit free water intake and address the underlying cause.	Fluid restriction, diuretics, and managing the core medical condition.

How to Safely Address Low Sodium

Treatment for hyponatremia must be carefully managed by a healthcare professional, as over-correction can cause serious neurological complications like osmotic demyelination syndrome. A doctor will first determine the underlying cause and severity.

For mild, chronic cases, treatment may involve:

Fluid Restriction: Limiting fluid intake to prevent further dilution of sodium.
Adjusting Medications: If a medication is the cause, the doctor may change the dosage or prescribe an alternative.
Dietary Adjustments: Incorporating naturally salty foods, as directed by a physician. Some foods that naturally contain sodium include cheese, meats, fish, and certain vegetables like beets and celery.
Electrolyte Drinks: Consuming sports drinks with electrolytes during intense exercise to replace lost sodium.

In severe, acute cases, immediate hospital treatment is required. This may involve intravenous sodium solutions to raise levels slowly and safely. It is critical not to attempt to self-treat severe hyponatremia at home.

Conclusion

While a low-salt diet is a risk factor, the query "why am I lacking in salt?" often points to more complex issues, primarily an imbalance between the body's sodium and water. Whether caused by over-hydration, medications, or underlying health conditions affecting organ function, symptoms can range from mild to life-threatening. Proper diagnosis by a healthcare professional is paramount for safe and effective treatment. By addressing the root cause, carefully managing fluid intake, and in some cases, adjusting medication, sodium levels can be restored to a healthy balance. If you experience any symptoms of low sodium, particularly severe confusion or seizures, seek immediate medical attention.

For more detailed information on hyponatremia and its management, consult authoritative sources like the Mayo Clinic.

Natural Sources of Sodium

Pickles & Sauerkraut: Fermented foods like pickled cucumbers and sauerkraut are naturally high in sodium.
Cottage Cheese: This dairy product provides a significant amount of sodium.
Soups & Broths: Both canned and homemade broths are excellent sources of sodium.
Seafood: Shrimp and other shellfish naturally contain higher levels of sodium.
Vegetable Juice: Canned vegetable juices, especially tomato juice, are often high in sodium.

High-Risk Groups for Hyponatremia

Endurance Athletes: High fluid intake combined with sweat-induced sodium loss can lead to low sodium levels.
Older Adults: Age-related changes and multiple medications increase the risk.
Individuals with Chronic Illnesses: Patients with heart, kidney, or liver disease are at higher risk.
Post-Surgery Patients: Pain and stress can increase antidiuretic hormone levels, leading to water retention.
People with Psychiatric Disorders: Conditions causing excessive thirst (polydipsia) can lead to over-hydration.
Users of Illicit Drugs: The recreational drug MDMA can increase vasopressin secretion and fluid intake, causing severe hyponatremia.

Frequently Asked Questions

In a medical context, low sodium and low salt are effectively the same thing. Salt is the common name for sodium chloride, and low blood sodium, or hyponatremia, is a condition where the concentration of sodium in your blood is lower than normal.

Yes, drinking excessive amounts of water can lead to hyponatremia. This happens because the extra fluid dilutes the sodium content in your blood, throwing off the body's delicate electrolyte balance.

Early symptoms are often mild and non-specific, including a headache, nausea, loss of energy, and fatigue. Some people may also experience muscle cramps or weakness.

For those recommended to increase sodium, foods like cheese, processed meats, salted nuts, canned soups, and broths are higher in sodium. Any dietary change should be guided by a doctor, particularly if underlying conditions exist.

You should contact your healthcare provider if you have symptoms like nausea, headaches, or weakness, especially if you have a medical condition that puts you at risk. If you experience severe symptoms like confusion, seizures, or lost consciousness, seek emergency care immediately.

SIADH stands for Syndrome of Inappropriate Antidiuretic Hormone. It is a medical condition where the body produces too much antidiuretic hormone, causing the body to retain water and dilute the blood's sodium level.

Yes, intense or prolonged exercise can cause hyponatremia, known as exertional hyponatremia. This is common in endurance athletes who sweat profusely, losing sodium, and then rehydrate with excessive amounts of plain water, further diluting their sodium concentration.

Yes, treating low sodium too rapidly can be very dangerous. It can lead to serious neurological complications, including osmotic demyelination syndrome, which is why correction must be done slowly under medical supervision.