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 12638-3: Glucose pre dose lactose PO [Mass/Vol]

Name: LOINC Code 12638-3: Glucose pre dose lactose PO [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:23.603Z

12638-3 is a LOINC code used to identify Glucose pre dose lactose PO [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^pre dose lactose PO. 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^pre dose lactose PO. 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 --pre dose lactose PO
Glucose^pre dose lactose PO
Before; CHEMISTRY.CHALLENGE TESTING; Endocrine; Endocrinology; Glu; Glu tol; Gluc; Glucose tolerance; Glucoseur; GTT; Level; LTT; Mass concentration; Pl; Plasma; Plsm; Point in time; pre Lac PO; 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 pre dose lactose PO [Mass/Vol]Glucose [Mass/volume] in Serum or Plasma --pre dose lactose POGlucose pre Lac PO SerPl-mCncGlucose^pre dose lactose POCHALGlucose before dose lactose by mouth, BloodMCnc

Frequently asked questions

Code details

Code12638-3

SystemLOINC

Display nameGlucose pre dose lactose PO [Mass/Vol]

DescriptionGlucose^pre dose lactose PO

Short nameGlucose pre Lac PO SerPl-mCnc

ComponentGlucose^pre dose lactose PO

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 released1.0j-a

Last changed2.73

Consumer names

Glucose before dose lactose by mouth, Blood

Part names

Glucose^pre dose lactose POMCncPtSer/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.