Sodium

Also known as: Serum Sodium, Na+

Kidney Blood
Patient Friendly Summary

Sodium is your body's water-balance thermostat. Mildly low values are a frequent lab finding in elderly patients — fixable, but the cause should be found rather than just adding salt.

What this test means

Sodium keeps the right amount of water inside and outside your cells. The body guards its level tightly; significant shifts affect the brain first.

Why it is done

It is done for weakness, confusion, vomiting or diarrhoea, with diuretic (water pill) medicines, and in kidney, heart, and liver conditions.

Understanding your value

If your value is high

High sodium usually reflects water loss or inadequate water intake, often seen with dehydration.

If your value is low

Low sodium is common in older adults and people on certain medicines; it can cause weakness, confusion, or unsteadiness and needs medical evaluation.

About the normal range

The common range is about 135–145 mEq/L. Even small deviations can matter, so doctors interpret this with your symptoms and fluid status.

When to consult a doctor

Consult your doctor for any flagged value. Seek care promptly for confusion, severe weakness, or repeated vomiting with an abnormal sodium.

Frequently Asked Questions

It is done for weakness, confusion, vomiting or diarrhoea, with diuretic (water pill) medicines, and in kidney, heart, and liver conditions. Your doctor will decide if this test is right for your situation.

High sodium usually reflects water loss or inadequate water intake, often seen with dehydration. This needs clinical correlation — always discuss your report with your doctor.

Low sodium is common in older adults and people on certain medicines; it can cause weakness, confusion, or unsteadiness and needs medical evaluation. This needs clinical correlation — always discuss your report with your doctor.

A single value rarely tells the whole story. Results need to be read together with your symptoms, history, and other tests. Please consult your doctor for a proper interpretation.

Quick Facts

  • TestSodium
  • Short formsSerum Sodium, Na+
  • Sample typeBlood
  • CategoryKidney

Related Terms

Low High Kidney Function

Specialists

Nephrology General Medicine

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Disclaimer: This information is for patient education only and does not replace medical advice, diagnosis, or treatment. Always consult a qualified doctor.