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 8646-2: Hospital admission diagnosis

Name: LOINC Code 8646-2: Hospital admission diagnosis
Creator: HealthAssure Clinical Team
Published: 2026-05-21T09:00:14.637Z

8646-2 is a LOINC code used to identify Hospital admission diagnosis 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 Hospital admission Dx. It is commonly used with the system or sample type ^Patient.

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 Hospital admission Dx. It is commonly used with the system or sample type ^Patient.

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

Hospital admission diagnosis
Hospital admission Dx
Diagnosis; H+P; H+P.HX; Hosp; Impression; Impression/interpretation of study; Impressions; Interp; Interpretation; Nominal; P prime; Point in time; Random

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

Hospital admission diagnosisHospital admission DxH&P.HXImpPt^PatientNom

Frequently asked questions

Code details

Code8646-2

SystemLOINC

Display nameHospital admission diagnosis

DescriptionHospital admission Dx

Short nameHospital admission Dx

ComponentHospital admission Dx

PropertyImp

TimingPt

System (specimen)^Patient

ScaleNom

ClassH&P.HX

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0h(3)

Last changed2.27

Part names

Hospital admission DxImpPt^PatientNomHospital admission diagnosisImpression/interpretation of studyPoint 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.