What is the amount of sodium in 1 unit of Normal Saline (NS)?

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Last updated: November 17, 2025View editorial policy

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Sodium Content in Normal Saline

One liter (1 unit) of Normal Saline (0.9% NaCl) contains 154 mmol (or mEq) of sodium.

Composition Details

Normal saline is a 0.9% sodium chloride solution, which translates to specific sodium content 1:

  • Sodium concentration: 154 mmol/L (or 154 mEq/L)
  • Chloride concentration: 154 mmol/L (or 154 mEq/L)
  • Total osmolarity: Approximately 308 mOsm/L

Practical Calculation

For different volumes of normal saline 1:

  • 1 liter (1000 mL): 154 mmol sodium
  • 500 mL: 77 mmol sodium
  • 250 mL: 38.5 mmol sodium
  • 100 mL bolus: 15.4 mmol sodium

Clinical Context

Normal saline is isotonic and commonly used for 1:

  • Volume resuscitation in hypovolemic states, where 1-2 liters may be administered to adults at 5-10 mL/kg in the first 5 minutes
  • Initial fluid replacement in anaphylaxis, where crystalloids up to 7 liters might be necessary
  • Treatment of hypovolemic hyponatremia, where the 154 mmol/L sodium concentration helps restore both volume and sodium balance

Comparison to Other Solutions

To provide context 2:

  • 3% hypertonic saline: 513 mmol/L sodium (more than 3 times the concentration of normal saline)
  • 0.45% saline (half-normal): 77 mmol/L sodium (half the concentration of normal saline)
  • Lactated Ringer's solution: 130 mmol/L sodium (slightly less than normal saline)

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Calculation of Table Salt in 3% Hypertonic Saline

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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