What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 39998-0: Glucose 30 Min pre Unsp challenge [Mass/Vol]

Name: LOINC Code 39998-0: Glucose 30 Min pre Unsp challenge [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:27.143Z

39998-0 is a LOINC code used to identify Glucose 30 Min pre Unsp challenge [Mass/Vol] 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 Glucose^30M pre XXX challenge. It is commonly used with the system or sample type Ser/Plas.

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 Glucose^30M pre XXX challenge. It is commonly used with the system or sample type Ser/Plas.

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

Glucose [Mass/volume] in Serum or Plasma --30 minutes pre XXX challenge
Glucose^30M pre XXX challenge
30M pre chal; Before; CHEMISTRY.CHALLENGE TESTING; Endocrine; Endocrinology; Glu; Glu tol; Gluc; Glucose tolerance; Glucoseur; GTT; Level; Mass concentration; Pl; Plasma; Plsm; Point in time; pre chal; QNT; Quan; Quant; Quantitative; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR

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

Glucose 30 Min pre Unsp challenge [Mass/Vol]Glucose [Mass/volume] in Serum or Plasma --30 minutes pre XXX challengeGlucose 30M pre chal SerPl-mCncGlucose^30M pre XXX challengeCHALGlucose 30 min before challenge, BloodMCnc

Frequently asked questions

Code details

Code39998-0

SystemLOINC

Display nameGlucose 30 Min pre Unsp challenge [Mass/Vol]

DescriptionGlucose^30M pre XXX challenge

Short nameGlucose 30M pre chal SerPl-mCnc

ComponentGlucose^30M pre XXX challenge

PropertyMCnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

ClassCHAL

Example unitsmg/dL

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.15

Last changed2.73

Consumer names

Glucose 30 min before challenge, Blood

Part names

Glucose^30M pre XXX challengeMCncPtSer/PlasQnMass ConcentrationPoint in time (spot)Serum or Plasma

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.