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 51491-9: Cortisol 4th specimen post Unsp challenge (Sal) [Mass/Vol]

Name: LOINC Code 51491-9: Cortisol 4th specimen post Unsp challenge (Sal) [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:35.012Z

51491-9 is a LOINC code used to identify Cortisol 4th specimen post Unsp challenge (Sal) [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 Cortisol^4th specimen post XXX challenge. It is commonly used with the system or sample type Saliva.

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 Cortisol^4th specimen post XXX challenge. It is commonly used with the system or sample type Saliva.

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

Cortisol [Mass/volume] in Saliva (oral fluid) --4th specimen post XXX challenge
Cortisol^4th specimen post XXX challenge
17-Hydroxycorticosterone; After; CHEMISTRY.CHALLENGE TESTING; Compound F; Coritsol; Cort; F; hydrocortisone; Level; Mass concentration; Oral fluid; p chal; Point in time; PST; QNT; Quan; Quant; Quantitative; Random; Sal; sp4; sp4 p chal; Spec

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

Cortisol 4th specimen post Unsp challenge (Sal) [Mass/Vol]Cortisol [Mass/volume] in Saliva (oral fluid) --4th specimen post XXX challengeCortis sp4 p chal Sal-mCncCortisol^4th specimen post XXX challengeCHALCortisol 4th specimen after challenge, SalivaMCnc

Frequently asked questions

Code details

Code51491-9

SystemLOINC

Display nameCortisol 4th specimen post Unsp challenge (Sal) [Mass/Vol]

DescriptionCortisol^4th specimen post XXX challenge

Short nameCortis sp4 p chal Sal-mCnc

ComponentCortisol^4th specimen post XXX challenge

PropertyMCnc

TimingPt

System (specimen)Saliva

ScaleQn

ClassCHAL

Example unitspg/mL;ug/dL

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.24

Last changed2.73

Consumer names

Cortisol 4th specimen after challenge, Saliva

Part names

Cortisol^4th specimen post XXX challengeMCncPtSalivaQnMass ConcentrationPoint 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.