Sodium (NA) | LabsVault

What is Sodium?

Sodium is the major extracellular cation (positively charged ion) that regulates fluid balance, blood pressure, and nerve function. It’s essential for maintaining proper hydration status and blood volume. Sodium levels reflect the balance between water and salt in the body and are tightly regulated by the kidneys and hormonal systems.

Why is it Tested?

Doctors order sodium to evaluate fluid and electrolyte balance, assess kidney function, and investigate symptoms like confusion, seizures, or muscle weakness. It’s crucial for monitoring patients with heart failure, kidney disease, or those taking medications affecting fluid balance. Sodium abnormalities can cause serious neurological complications.

Normal Ranges

Reference ranges vary by lab. General adult guidelines:

Adults: 136–145 mmol/L

Reference ranges vary by authority. Track yours across multiple standards with automatic unit conversions in LabsVault.

What do Abnormal Results Mean?

Abnormal results are not a diagnosis. Always discuss your results with a qualified healthcare provider before making any medical decisions.

Low Sodium

Low sodium (hyponatremia) may indicate:

Excessive water intake or retention
Heart failure or liver disease
Certain medications (diuretics, antidepressants)
Syndrome of inappropriate antidiuretic hormone (SIADH)

High Sodium

Elevated sodium (hypernatremia) usually indicates dehydration and may point to:

Inadequate water intake
Excessive water loss (diabetes insipidus)
Salt poisoning or excessive sodium intake
Certain medications or medical conditions

How to Track Over Time

Sodium monitoring helps assess fluid balance and hydration status over time. Gradual changes may indicate developing kidney or heart problems, while acute changes often reflect dehydration, medication effects, or hormonal imbalances. Consistent tracking helps prevent serious complications from sodium imbalances.

Sodium