The normal range of serum sodium in human body is -

Appeared in: UPPSC 2023

Explanation

The accepted normal range for serum sodium in adults is 135-145 mEq/L.
Sodium is the most abundant cation (positively charged ion) in the extracellular fluid (ECF).
Its primary function is to regulate the volume and osmolality of the ECF, which directly impacts blood pressure and fluid balance.
Sodium is also essential for the transmission of nerve impulses and the contraction of muscles.

Option A: The range of 21-29 mEq/L represents the normal value for serum bicarbonate (HCO₃⁻), not sodium.
Option B: The range of 95-107 mEq/L is the approximate normal value for serum chloride (Cl⁻).
Option C: The range of 3.6-5.0 mEq/L represents the normal value for serum potassium (K⁺).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Normal Serum Electrolyte Values as background academic context rather than a clinical decision trigger.
Nurses must constantly monitor electrolyte levels, as imbalances can lead to life-threatening conditions. Sodium levels are particularly important in patients with heart failure, kidney disease, endocrine disorders, or those receiving IV fluid therapy.
Deviations from the normal sodium range require prompt nursing intervention. Hyponatremia (low sodium) can cause confusion and seizures, while hypernatremia (high sodium) can lead to dehydration and neurological changes.
What if? A patient's lab results show a sodium level of 128 mEq/L (hyponatremia). The nurse's priority is to implement safety measures, such as seizure precautions, due to the risk of neurological complications from cerebral edema, and to notify the healthcare provider immediately.

How to Approach the Question

This is a factual recall question that tests foundational knowledge of common laboratory values.
First, identify the specific substance the question is asking about, which is 'serum sodium'.
Next, recall the standard normal range for that substance from your studies. The normal range for sodium is 135-145 mEq/L.
Scan the options to find the one that matches your recalled knowledge.
To confirm your answer, mentally identify the lab values represented by the other options (distractors). Recognizing that the other options represent normal ranges for potassium, chloride, and bicarbonate reinforces that your chosen answer is correct.

Concept Tested & Keywords

QioOCpCU2c3wbkPb2wAKqn

E6 Nursing Fundamentals Potter Perry 12e Part 5 p. 47-49

E6 Nursing Brunner Adult Health 3SA Vol 1 Part 1 p. 134-136

E6 Nursing Fundamentals Potter Perry 12e Part 6 p. 178-180

Practise the full UPPSC 2023

Attempt every question from this paper in a timed mock, then review the full solution for each one.