Sodium is an important electrolyte that plays a key role in maintaining water balance, blood pressure, and nerve and muscle function.

Abnormal levels of sodium, whether too high or too low, can interfere with these critical functions. For example:

• Hyponatremia (low sodium) : May cause confusion, fatigue, and severe symptoms in extreme cases.
• Hypernatremia (high sodium) : May cause high blood pressure and kidney damage.

These properties make sodium a key biomarker for evaluating several health conditions.

Sodium testing is often included in routine health checkups. It is also prescribed in specific situations, such as:

• General electrolyte balance : Performed during routine analyses.
• Assessment of dehydration or water imbalance.
• Diagnosis or follow-up of kidney disease.
• Hyponatremia symptoms : Confusion, fatigue, nausea.
• Hypernatremia symptoms : Increased thirst, muscle weakness.
• Dermatological or hair problems : Likely to be linked to an electrolyte imbalance.

Sodium levels can be measured via blood tests, urine tests, hair tests, or even fingernails.

Test methods:

1. Blood test (serum sodium) : The most common method, often included in comprehensive metabolic panels (CMP) or basic metabolic panels (BMP).
2. Urine test : Evaluates sodium retention or kidney function.
   • Preparation : Avoid diuretics 2 days before unless otherwise directed by your doctor.
3. Hair or nail test : Measures sodium accumulated over the long term (5 to 8 weeks).
   • Preparation : Avoid hair treatments (coloring, perming) before the test.

• Adults : 135 to 145 mmol/L in the blood.
• Urine (24 hours) : 40 to 220 mmol/L, depending on food intake.

note : The normal ranges may vary depending on the laboratory and the techniques used.

High Sodium Levels (Hypernatremia)

High levels often indicate dehydration or fluid imbalance.

Common causes:

• Cushing's syndrome : Excessive production of cortisol leading to sodium retention.
• Kidney disease : Disrupts sodium regulation.
• Hyperaldosteronism : Excess aldosterone increasing sodium retention.
• Diabetes mellitus : May contribute to electrolyte imbalances.
• Bartter syndrome : A genetic disorder affecting salt metabolism by the kidneys.

Recommendations:

• Work with a doctor to identify the underlying cause.
• Hydrate yourself regularly, especially after physical activity or in hot weather.
• Limit salt intake in your diet.
• Manage underlying conditions associated with hypernatremia.

Low Sodium Levels (Hyponatremia)

Low sodium levels upset the fluid balance and can lead to severe symptoms.

Common causes:

• Hypothyroidism : Affects sodium regulation.
• Fluid loss : Excessive sweating, vomiting, or diarrhea.
• Malabsorption : Disorders like celiac disease.
• Heart failure : May cause sodium levels to dilute.
• Severe vomiting/diarrhea : Cause rapid sodium losses.

Recommendations:

• Consult a doctor to determine the cause.
• Drink water in moderation to avoid further dilution.
• Avoid excessive alcohol that upsets the electrolyte balance.
• Eat foods that are high in protein and salt in balanced amounts.

The specialist depends on the symptoms and the underlying cause:

• General practitioner : For an initial assessment.
• Nephrologist : If sodium levels are linked to kidney disease.
• Cardiologist : For sodium problems related to cardiovascular health.
• Neurologist : If neurological symptoms occur.
• Dermatologist : In case of skin or hair problems associated with an imbalance.

Prompt consultation is essential to effectively manage sodium imbalances and avoid complications.