LOINCActiveObservation

LOINC Code 104982-4: Reaction presence

104982-4 is a LOINC code used to identify Reaction presence 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 Reaction presence. It is commonly used with the system or sample type ^Patient.

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 Reaction presence. It is commonly used with the system or sample type ^Patient.

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

  • Reaction presence
  • ADMIN; Finding; Findings; Nominal; Point in time; Random; React; Rxn

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

Reaction presenceADMINFindPt^PatientNomFinding

Frequently asked questions

Code details

Code104982-4
SystemLOINC
Display nameReaction presence
Short nameReaction presence
ComponentReaction presence
PropertyFind
TimingPt
System (specimen)^Patient
ScaleNom
ClassADMIN
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.78
Last changed2.78

Part names

Reaction presenceFindPt^PatientNomFindingPoint in time (spot)

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 104982-4 | HealthAssure