LOINCActiveBoth

LOINC Code 53555-9: Specific gravity (RBC)

53555-9 is a LOINC code used to identify Specific gravity (RBC) in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Observation. It is commonly used with the system or sample type RBC.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Observation. It is commonly used with the system or sample type RBC.

When is it used?

  • Used in lab systems, EHRs, and clinical data exchange.
  • May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
  • Status: ACTIVE
  • Order vs observation: Both

What it does not mean

  • The code identifies the observation or test, not the actual result.

Key facts

  • Specific gravity of Red Blood Cells
  • Observation
  • Chemistry; Erythrocytes; Point in time; QNT; Quan; Quant; Quantitative; Random; Red blood cells; Red blood corpusles; Sp Gr

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Specific gravity (RBC)Specific gravity of Red Blood CellsSp Gr RBCObservationCHEMSpecific gravity, Red blood cellsSpGrav

Frequently asked questions

Code details

Code53555-9
SystemLOINC
Display nameSpecific gravity (RBC)
DescriptionObservation
Short nameSp Gr RBC
ComponentObservation
PropertySpGrav
TimingPt
System (specimen)RBC
ScaleQn
ClassCHEM
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.26
Last changed2.79

Consumer names

Specific gravity, Red blood cells

Part names

ObservationSpGravPtRBCQnSpecific gravityPoint in time (spot)Red Blood Cells

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

LOINC Code 53555-9 | HealthAssure