What is the normal range for specific gravity of urine?

Appeared in: DSSSB -28 August 2019 (Shift-2)

Explanation

The normal range for urine specific gravity in adults is 1.010 to 1.030.
This value measures the density of urine compared to water (1.000) and reflects the concentration of dissolved solutes.
It serves as a primary indicator of a patient's hydration status and the functional ability of the kidneys to concentrate or dilute urine.
Values within this range typically signify adequate hydration and normal kidney function.

Option A: This range (1.006 to 1.010) represents dilute urine, which is below the standard normal range. A value fixed at 1.010 is known as isosthenuria.
Option B: This range (1.01 to 1.10) is incorrectly formatted and the upper limit of 1.10 is physiologically impossible for human urine.
Option C: This range (1.100 to 1.160) is physiologically impossible for urine specific gravity. Such high values are not compatible with human physiology.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Normal range of urine specific gravity as background academic context rather than a clinical decision trigger.
Nurses frequently use a dipstick urinalysis at the bedside to quickly assess a patient's hydration status and screen for kidney or metabolic disorders.
A high specific gravity can prompt the nurse to assess for signs of dehydration (e.g., poor skin turgor, dry mucous membranes, low urine output) and encourage fluid intake or administer IV fluids as ordered.
A consistently low specific gravity may indicate conditions like diabetes insipidus or chronic kidney disease, requiring further investigation and careful fluid balance monitoring.

How to Approach the Question

Identify the core concept of the question, which is the 'normal range for specific gravity of urine'.
Recognize this as a factual recall question that requires knowledge of standard laboratory values.
Recall the typical physiological range for urine specific gravity. Remember that urine is denser than pure water (1.000).
Evaluate the given options. Eliminate any ranges that are physiologically impossible (e.g., values greater than 1.040 are highly suspect and 1.100 is impossible) or represent abnormal states (e.g., values below 1.010 indicate very dilute urine).
Select the option that best represents the accepted clinical standard for a healthy adult, which allows for variations in hydration.

Concept Tested & Keywords

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E6 Nursing Brunner Adult Health 3SA Vol 2 Part 1 p. 132-134

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 2 — Subpart A (pp 1-239 of 478) p. 47-49

Practise the full DSSSB -28 August 2019 (Shift-2)

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