LOINCActiveObservation

LOINC Code 90556-2: Obstructive hypopnea [#]

90556-2 is a LOINC code used to identify Obstructive hypopnea [#] 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 Obstructive hypopnea. 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 Obstructive hypopnea. 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

  • Obstructive hypopnea [#]
  • Obstructive hypopnea
  • The sum of all obstructive hypopneas identified during the sleep time of the polysomnography (PSG) study.
  • Cnt; Count; Ear Nose Throat; ENT; Lung; Number; Oto; Otolaryngology; Pulmonary; Pulmonology; QNT; Quan; Quant; Quantitative; Respiratory; Studies; Study; Sutdies

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

Obstructive hypopnea [#]Num obstructive hypopneaObstructive hypopneaPULMNumStdy^Patient

Frequently asked questions

Code details

Code90556-2
SystemLOINC
Display nameObstructive hypopnea [#]
DescriptionObstructive hypopnea
Short nameNum obstructive hypopnea
ComponentObstructive hypopnea
PropertyNum
TimingStdy
System (specimen)^Patient
ScaleQn
ClassPULM
Example units#
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.65
Last changed2.65

Part names

Obstructive hypopneaNumStdy^PatientQnNumber (count)Study

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 90556-2 | HealthAssure