LOINCActive

LOINC Code 34538-9: Orthostatic blood pressure

34538-9 is a LOINC code used to identify Orthostatic blood pressure 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 Orthostatic blood pressure. It is commonly used with the system or sample type Arterial system.

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 Orthostatic blood pressure. It is commonly used with the system or sample type Arterial system.

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

What it does not mean

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

Key facts

  • Orthostatic blood pressure
  • According to the American Academy of Neurology, the formal diagnosis of orthostatic hypotension requires a 20mm drop in systolic blood pressure or a 10mm drop in diastolic blood pressure within three minutes of standing. Often there is an associated increase in the heart rate, especially if dehydration or bleeding is the cause. (if the patient is taking a beta blocker, the heart rate may not be able to respond with an increase).
  • Art sys; BLOOD PRESSURE MEASUREMENTS.POSITION.MOLEC; BP; Orthostatic BP; Point in time; Position; QNT; Quan; Quant; Quantitative; 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

Orthostatic blood pressureOrthostatic BPBP.PSTN.MOLECPressDiffPtArterial systemQn

Frequently asked questions

Code details

Code34538-9
SystemLOINC
Display nameOrthostatic blood pressure
Short nameOrthostatic BP
ComponentOrthostatic blood pressure
PropertyPressDiff
TimingPt
System (specimen)Arterial system
ScaleQn
ClassBP.PSTN.MOLEC
Example unitsmm Hg
StatusACTIVE

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.10
Last changed2.73

Part names

Orthostatic blood pressurePressDiffPtArterial systemQnPressure DifferencePoint 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 34538-9 | HealthAssure