LOINCActiveObservation

LOINC Code 55942-7: Methemoglobin (BldCo) [Mass fraction]

55942-7 is a LOINC code used to identify Methemoglobin (BldCo) [Mass fraction] 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 Methemoglobin/Hemoglobin.total. It is commonly used with the system or sample type BldCo.

Reviewed by HealthAssure Clinical TeamUpdated 25 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 Methemoglobin/Hemoglobin.total. It is commonly used with the system or sample type BldCo.

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

  • Methemoglobin/Hemoglobin.total in Cord blood
  • Methemoglobin/Hemoglobin.total
  • Blood - (umbilical) cord; Chemistry; Cord (umbilical) blood; Cord bld; Cord blood; Haemoglobin; Hb; Hemiglobin; Hgb; Hi; Mass fraction; Methaemoglobin; MetHb; Methgb; Percent; Point in time; QNT; Quan; Quant; Quantitative; Random; Tot; Totl

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

Methemoglobin (BldCo) [Mass fraction]Methemoglobin/Hemoglobin.total in Cord bloodMetHgb MFr BldCoMethemoglobin/Hemoglobin.totalCHEMMethemoglobin/Total Hgb, Cord bloodMFr

Frequently asked questions

Code details

Code55942-7
SystemLOINC
Display nameMethemoglobin (BldCo) [Mass fraction]
DescriptionMethemoglobin/Hemoglobin.total
Short nameMetHgb MFr BldCo
ComponentMethemoglobin/Hemoglobin.total
PropertyMFr
TimingPt
System (specimen)BldCo
ScaleQn
ClassCHEM
Example units%
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.29
Last changed2.70

Consumer names

Methemoglobin/Total Hgb, Cord blood

Part names

Methemoglobin/Hemoglobin.totalMFrPtBldCoQnMass fractionPoint in time (spot)Blood cord

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 55942-7 | HealthAssure