Equis ISSN 2398-2977

Urine: specific gravity

Contributor(s): Annalisa Barrelet

Overview

  • Measurement of kidneys' ability to concentrate and dilute urine.

Sampling

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Tests

Methodologies

Refractometer
  • Single drop placed on glass surface; reading relative to specific gravity of distilled water (= 1).

Urinometer

  • Need large volume (15-45 ml), but can dilute and recalculate specific gravity reading.
  • Three-quarter fill cylinder then insert urinometer and read scale at interface of air with urine; the scale reading represents the 2nd and 3rd decimal placing, eg reading of 25 = 1.025.

Dipstick

  • Results do not correlate well with refractometer.

Availability

  • Standard practice laboratory technique.

Technique (intrinsic) limitations

  • Cannot interpret results in isolation from other urinalysis results and lab tests.
  • Single random result outside normal reference range cannot establish diagnosis.

Result Data

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Further Reading

Publications

Refereed papers

  • Recent references fromPubMedpublished during the last 12 months.


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