LOINCActiveObservation

LOINC Code 19158-5: Urea nitrogen comment Nar (24H U) [Interp]

19158-5 is a LOINC code used to identify Urea nitrogen comment Nar (24H U) [Interp] 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 Urea nitrogen comment. It is commonly used with the system or sample type Urine.

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 Urea nitrogen comment. It is commonly used with the system or sample type Urine.

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: Observation

What it does not mean

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

Key facts

  • Urea nitrogen comment - 24 hour Urine Narrative
  • Urea nitrogen comment
  • 1 day; 24 hours; 24HR; Blood urea nitrogen; Chemistry; cmmt; cmnt; Com; Comm; Comments; Commt; Impression; Impression/interpretation of study; Impressions; Interp; Interpretation; N; N2; Narrative; Nit; Remarks; Report; UA; UN; UR; Urea Nit Cmnt; Urn; UUN

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

Urea nitrogen comment Nar (24H U) [Interp]Urea nitrogen comment - 24 hour Urine NarrativeUUN 24h Ur-ImpUrea nitrogen commentCHEMInterpretation of Urea nitrogen comment test result, UrineImp

Frequently asked questions

Code details

Code19158-5
SystemLOINC
Display nameUrea nitrogen comment Nar (24H U) [Interp]
DescriptionUrea nitrogen comment
Short nameUUN 24h Ur-Imp
ComponentUrea nitrogen comment
PropertyImp
Timing24H
System (specimen)Urine
ScaleNar
ClassCHEM
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0l
Last changed2.26

Consumer names

Interpretation of Urea nitrogen comment test result, Urine

Part names

Urea nitrogen commentImp24HUrineNarImpression/interpretation of study24 hours

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 19158-5 | HealthAssure