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 104642-4: Time below range, very low Calc (Reporting Period Interstitial fluid)

Name: LOINC Code 104642-4: Time below range, very low Calc (Reporting Period Interstitial fluid)
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:19.128Z

104642-4 is a LOINC code used to identify Time below range, very low Calc (Reporting Period Interstitial fluid) 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 Time below range, very low. It is commonly used with the system or sample type Interstitial fluid.

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 Time below range, very low. It is commonly used with the system or sample type Interstitial fluid.

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
Method: Calculated

What it does not mean

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

Key facts

Time below range, very low in Reporting Period Interstitial fluid by calculation
Time below range, very low
Calc; Calculation; Chemistry; Interstitial fld; Number Fraction; Percent; QNT; Quan; Quant; Quantitative; Report period; Rnge; Time very low hypo

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

Time below range, very low Calc (Reporting Period Interstitial fluid)Time below range, very low in Reporting Period Interstitial fluid by calculationRptPeriod NFr Interstitial fld CalcTime below range, very lowCHEMTime below range, very low, Interstitial fluidNFr

Frequently asked questions

Code details

Code104642-4

SystemLOINC

Display nameTime below range, very low Calc (Reporting Period Interstitial fluid)

DescriptionTime below range, very low

Short nameRptPeriod NFr Interstitial fld Calc

ComponentTime below range, very low

PropertyNFr

TimingRptPeriod

System (specimen)Interstitial fluid

ScaleQn

MethodCalculated

ClassCHEM

Example units%

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.79

Last changed2.79

Consumer names

Time below range, very low, Interstitial fluid

Part names

Time below range, very lowNFrRptPeriodInterstitial fluidQnCalculatedNumber FractionReporting Period

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.