LOINCActiveObservation

LOINC Code 20201-0: Circulatory system [Identifier]

20201-0 is a LOINC code used to identify Circulatory system [Identifier] 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 Circulatory system. It is commonly used with the system or sample type *.

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 Circulatory system. It is commonly used with the system or sample type *.

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

  • Circulatory system [Identifier]
  • Circulatory system
  • CARD.US; Cardio; Cardiology; Circ sys; Heart Disease; Identity or presence; Nominal; Point in time; Random; Ultrasound

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

Circulatory system [Identifier]Circ sysCirculatory systemCARD.USPridPt*

Frequently asked questions

Code details

Code20201-0
SystemLOINC
Display nameCirculatory system [Identifier]
DescriptionCirculatory system
Short nameCirc sys
ComponentCirculatory system
PropertyPrid
TimingPt
System (specimen)*
ScaleNom
ClassCARD.US
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0m
Last changed2.27

Part names

Circulatory systemPridPt*NomPresence or IdentityPoint 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.

LOINC Code 20201-0 | HealthAssure