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.

LOINCActive

LOINC Code 43257-5: FEV1 --post 2.5 mg/mL methacholine

Name: LOINC Code 43257-5: FEV1 --post 2.5 mg/mL methacholine
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:28.587Z

43257-5 is a LOINC code used to identify FEV1 --post 2.5 mg/mL methacholine 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 Volume expired during 1.0 s of forced expiration^post 2.5 mg/mL methacholine. It is commonly used with the system or sample type Respiratory system.

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 Volume expired during 1.0 s of forced expiration^post 2.5 mg/mL methacholine. It is commonly used with the system or sample type Respiratory system.

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

What it does not mean

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

Key facts

FEV1 --post 2.5 mg/mL methacholine
Volume expired during 1.0 s of forced expiration^post 2.5 mg/mL methacholine
After; Breathing; End tidal volume; Exp; FEV; FEV1; Forced expiratory volume in 1 second; Lung; Lungs; MECH; p 2.5 mg/mL MECH; Point in time; Provocholine; PST; PULMONARY; Pulmonology; QNT; Quan; Quant; Quantitative; Random; Respiratory; RS; S prime; Vet; Vol; Vol exp; Volume

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

FEV1 --post 2.5 mg/mL methacholineFEV1 p 2.5 mg/mL MECHVolume expired during 1.0 s of forced expiration^post 2.5 mg/mL methacholinePULMVolPtRespiratory system

Frequently asked questions

Code details

Code43257-5

SystemLOINC

Display nameFEV1 --post 2.5 mg/mL methacholine

DescriptionVolume expired during 1.0 s of forced expiration^post 2.5 mg/mL methacholine

Short nameFEV1 p 2.5 mg/mL MECH

ComponentVolume expired during 1.0 s of forced expiration^post 2.5 mg/mL methacholine

PropertyVol

TimingPt

System (specimen)Respiratory system

ScaleQn

ClassPULM

StatusACTIVE

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.17

Last changed2.64

Part names

Volume expired during 1.0 s of forced expiration^post 2.5 mg/mL methacholineVolPtRespiratory systemQnVolumePoint 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.