Subscribe for unlimited access to DynaMed content, CME/CE & MOC credit, and email alerts on content you follow.

Already subscribed? Sign in now


Orthostatic Hypotension and Orthostatic Syncope

General Information


  • orthostatic hypotension is a reduction in systolic blood pressure due to orthostatic stress, common in older patients that may result in syncope4
  • syncope is syndrome of transient loss of consciousness secondary to cerebral hypoperfusion characterized by rapid onset, short duration, and complete spontaneous recovery2,5


  • orthostatic hypotension
    • ≥ 20-mm Hg decrease in systolic blood pressure or ≥ 10-mm Hg decrease in diastolic blood pressure within 3 minutes of standing compared to sitting or supine1,2,3,4,5
    • decrease in systolic blood pressure ≥ 30 mm Hg in patients with hypertension (supine systolic blood pressure ≥ 160 mm Hg)3,4
    • absolute standing systolic blood pressure < 90 mm Hg in patients with low baseline supine blood pressure (< 110 mm Hg) is considered a useful definition by European Society of Cardiology but not by American College of Cardiology/American Heart Association/Heart Rhythm Society2,4,5
  • orthostatic syncope due to blood loss characterized by severe postural dizziness or postural pulse increment 30 beats/minute
  • orthostatic intolerance - reduced ability to maintain upright position due to circulatory abnormalities associated with frequent, recurrent, or persistent symptoms, such as light-headedness, palpitations, tremulousness, generalized weakness, blurred vision, exercise intolerance, or fatigue upon standing2,4,5
  • neurogenic orthostatic hypotension - orthostatic hypotension due to autonomic failure and not solely due to environmental triggers2,5
  • orthostatic hypotension can be classified by onset of reduction in systolic blood pressure
    • classic orthostatic hypotension
      • ≥ 20-mm Hg decrease in systolic blood pressure or ≥ 10-mm Hg decrease in diastolic blood pressure within 3 minutes of standing2,4,5
      • can be asymptomatic or symptomatic depending on absolute blood pressure values (syncope rare)2
    • initial orthostatic hypotension
      • ≥ 40-mm Hg decrease in systolic blood pressure or ≥ 20-mm Hg decrease in diastolic blood pressure within 15 seconds of standing followed by spontaneous and rapid normalization2,4
      • duration of hypotension and symptoms < 40 seconds but can still cause syncope2
    • delayed (progressive) orthostatic hypotension
      • ≥ 20-mm Hg decrease in systolic blood pressure or ≥ 10-mm Hg in diastolic blood pressure that occurs > 3 minutes after upright posture2
      • drop in blood pressure is progressive2,5
      • may have rapid syncope ≥ 3 minutes after standing (19713422Eur Heart J 2009 Nov;30(21):2631)
      • common among older adults2
      • may be confused with vasodepressive type of neurally mediated syncope (absence of bradycardia suggests delayed orthostatic hypotension)2,5


General references used

  1. Lanier JB, Mote MB, Clay EC. Evaluation and management of orthostatic hypotension. Am Fam Physician. 2011 Sep 1;84(5):527-36full-text
  2. Brignole M, Moya A, de Lange FJ, et al. 2018 ESC Guidelines for the diagnosis and management of syncope. Eur Heart J. 2018 Jun 1;39(21):1883-1948
  3. Freeman R, Wieling W, Axelrod FB, et al. Consensus statement on the definition of orthostatic hypotension, neurally mediated syncope and the postural tachycardia syndrome. Clin Auton Res. 2011 Apr;21(2):69-72
  4. Chisholm P, Anpalahan M. Orthostatic hypotension - pathophysiology, assessment, treatment, and the paradox of supine hypertension - a review. Intern Med J 2017 Apr;47(4):370
  5. Shen WK, Sheldon RS, Benditt DG, et al. 2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients With Syncope: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society. J Am Coll Cardiol 2017 Aug 1;70(5):620

Recommendation grading systems used

  • American College of Cardiology/American Heart Association/Heart Rhythm Society (ACC/AHA/HRS) grading system for recommendations
    • classifications of recommendations
      • Class I - procedure or treatment should be performed or administered
      • Class IIa - reasonable to perform procedure or administer treatment, but additional studies with focused objectives needed
      • Class IIb - procedure or treatment may be considered; additional studies with broad objectives needed, additional registry data would be useful
      • Class III - procedure or treatment should not be performed or administered because it is not helpful or may be harmful
        • Class III ratings may be subclassified as Class III No Benefit or Class III Harm
    • levels of evidence
      • Level A - high-quality evidence from > 1 randomized controlled trial or meta-analysis of high-quality randomized controlled trials
      • Level B-R - moderate-quality evidence from ≥ 1 randomized controlled trial or meta-analysis of moderate-quality randomized controlled trials
      • Level B-NR - moderate-quality evidence from ≥ 1 well-designed nonrandomized trial, observational studies, or registry studies, or meta-analysis of such studies
      • Level C-LD - randomized or nonrandomized studies with methodological limitations or meta-analyses of such studies
      • Level C-EO - consensus of expert opinion based on clinical experience
  • American Geriatrics Society (AGS) Beers Criteria grading system for recommendations
    • strength of recommendation
      • Strong - benefits clearly outweigh harms, adverse events, and risks, or harms, adverse events, and risks clearly outweigh benefits
      • Weak - benefits may not outweigh harms, adverse events, and risks
      • Insufficient - evidence inadequate to determine net harms, adverse events, and risks
    • quality of evidence
      • High - evidence includes consistent results from well-designed, well-conducted studies in representative populations that directly assess effects on health outcomes, based on either
        • ≥ 2 consistent, higher-quality randomized controlled trials
        • multiple, consistent observational studies with no significant methodological flaws showing large effects
      • Moderate - evidence sufficient to determine risks of adverse outcomes
        • strength of evidence limited by any of
          • number, quality, size, or consistency of included studies
          • generalizability to routine practice
          • indirect nature of evidence on health outcomes
        • based on any of
          • ≥ 1 higher-quality trial with > 100 participants
          • ≥ 2 higher-quality trials with some inconsistency
          • ≥ 2 consistent, lower-quality trials
          • multiple, consistent observational studies with no significant methodological flaws showing at least moderate effects
      • Low - evidence insufficient to assess harms or risks in health outcomes due to any of
        • limited number or power of studies
        • large and unexplained inconsistency between higher-quality studies
        • important flaws in study design or conduct
        • gaps in chain of evidence
        • lack of information on important health outcomes
    • Reference - AGS 2015 updated Beers Criteria for potentially inappropriate medication use in older adults (26446832J Am Geriatr Soc 2015 Nov;63(11):2227), commentary can be found in 27100608J Am Geriatr Soc 2016 Apr;64(4):920
  • European Society of Cardiology (ESC) grading system for recommendations
    • classes of recommendations
      • Class I - evidence and/or general agreement that treatment or procedure is beneficial, useful, effective
      • Class II - conflicting evidence and/or divergence of opinion about usefulness/efficacy of treatment or procedure
        • Class IIa - weight of evidence/opinion in favor of usefulness/efficacy
        • Class IIb - weight of usefulness/efficacy less well established by evidence/opinion
      • Class III - evidence or general agreement that given treatment or procedure is not useful/effective and may be harmful in some cases
    • levels of evidence
      • Level A - data from multiple randomized trials or meta-analyses
      • Level B - data from single randomized trial or large nonrandomized studies
      • Level C - expert consensus opinion and/or small studies, retrospective studies, or registries
    • Reference - European Society of Cardiology (ESC) guideline on diagnosis and management of syncope (29562304Eur Heart J 2018 Jun 1;39(21):1883)

Synthesized Recommendation Grading System for DynaMed Content

  • The DynaMed Team systematically monitors clinical evidence to continuously provide a synthesis of the most valid relevant evidence to support clinical decision-making (see 7-Step Evidence-Based Methodology).
  • Guideline recommendations summarized in the body of a DynaMed topic are provided with the recommendation grading system used in the original guideline(s), and allow users to quickly see where guidelines agree and where guidelines differ from each other and from the current evidence.
  • In DynaMed content, we synthesize the current evidence, current guidelines from leading authorities, and clinical expertise to provide recommendations to support clinical decision-making in the Overview & Recommendations section.
  • We use the Grading of Recommendations Assessment, Development and Evaluation (GRADE) to classify synthesized recommendations as Strong or Weak.
    • Strong recommendations are used when, based on the available evidence, clinicians (without conflicts of interest) consistently have a high degree of confidence that the desirable consequences (health benefits, decreased costs and burdens) outweigh the undesirable consequences (harms, costs, burdens).
    • Weak recommendations are used when, based on the available evidence, clinicians believe that desirable and undesirable consequences are finely balanced, or appreciable uncertainty exists about the magnitude of expected consequences (benefits and harms). Weak recommendations are used when clinicians disagree in judgments of relative benefit and harm, or have limited confidence in their judgments. Weak recommendations are also used when the range of patient values and preferences suggests that informed patients are likely to make different choices.
  • DynaMed synthesized recommendations (in the Overview & Recommendations section) are determined with a systematic methodology:
    • Recommendations are initially drafted by clinical editors (including ≥ 1 with methodological expertise and ≥ 1 with content domain expertise) aware of the best current evidence for benefits and harms, and the recommendations from guidelines.
    • Recommendations are phrased to match the strength of recommendation. Strong recommendations use "should do" phrasing, or phrasing implying an expectation to perform the recommended action for most patients. Weak recommendations use "consider" or "suggested" phrasing.
    • Recommendations are explicitly labeled as Strong recommendations or Weak recommendations when a qualified group has explicitly deliberated on making such a recommendation. Group deliberation may occur during guideline development. When group deliberation occurs through DynaMed Team-initiated groups:
      • Clinical questions will be formulated using the PICO (Population, Intervention, Comparison, Outcome) framework for all outcomes of interest specific to the recommendation to be developed.
      • Systematic searches will be conducted for any clinical questions where systematic searches were not already completed through DynaMed content development.
      • Evidence will be summarized for recommendation panel review including for each outcome, the relative importance of the outcome, the estimated effects comparing intervention and comparison, the sample size, and the overall quality rating for the body of evidence.
      • Recommendation panel members will be selected to include at least 3 members that together have sufficient clinical expertise for the subject(s) pertinent to the recommendation, methodological expertise for the evidence being considered, and experience with guideline development.
      • All recommendation panel members must disclose any potential conflicts of interest (professional, intellectual, and financial), and will not be included for the specific panel if a significant conflict exists for the recommendation in question.
      • Panel members will make Strong recommendations if and only if there is consistent agreement in a high confidence in the likelihood that desirable consequences outweigh undesirable consequences across the majority of expected patient values and preferences. Panel members will make Weak recommendations if there is limited confidence (or inconsistent assessment or dissenting opinions) that desirable consequences outweigh undesirable consequences across the majority of expected patient values and preferences. No recommendation will be made if there is insufficient confidence to make a recommendation.
      • All steps in this process (including evidence summaries which were shared with the panel, and identification of panel members) will be transparent and accessible in support of the recommendation.
    • Recommendations are verified by ≥ 1 editor with methodological expertise, not involved in recommendation drafting or development, with explicit confirmation that Strong recommendations are adequately supported.
    • Recommendations are published only after consensus is established with agreement in phrasing and strength of recommendation by all editors.
    • If consensus cannot be reached then the recommendation can be published with a notation of "dissenting commentary" and the dissenting commentary is included in the topic details.
    • If recommendations are questioned during peer review or post publication by a qualified individual, or reevaluation is warranted based on new information detected through systematic literature surveillance, the recommendation is subject to additional internal review.

DynaMed Editorial Process

  • DynaMed topics are created and maintained by the DynaMed Editorial Team and Process.
  • All editorial team members and reviewers have declared that they have no financial or other competing interests related to this topic, unless otherwise indicated.
  • DynaMed content includes Practice-Changing Updates, with support from our partners, McMaster University and F1000.

Special acknowledgements

On behalf of the American College of Physicians
  • Barbara Turner, MD, MSEd, MACP, ACP Deputy Editor, Clinical Decision Resource, as part of the ACP-EBSCO Health collaboration, managed the ACP peer review of the Overview and Recommendations section and related clinical content in this topic.
  • DynaMed topics are written and edited through the collaborative efforts of the above individuals. Deputy Editors, Section Editors, and Topic Editors are active in clinical or academic medical practice. Recommendations Editors are actively involved in development and/or evaluation of guidelines.
  • Editorial Team role definitions
    Topic Editors define the scope and focus of each topic by formulating a set of clinical questions and suggesting important guidelines, clinical trials, and other data to be addressed within each topic. Topic Editors also serve as consultants for the internal DynaMed Editorial Team during the writing and editing process, and review the final topic drafts prior to publication.
    Section Editors have similar responsibilities to Topic Editors but have a broader role that includes the review of multiple topics, oversight of Topic Editors, and systematic surveillance of the medical literature.
    Recommendations Editors provide explicit review of Overview and Recommendations sections to ensure that all recommendations are sound, supported, and evidence-based. This process is described in "Synthesized Recommendation Grading."
    Deputy Editors oversee DynaMed internal publishing groups. Each is responsible for all content published within that group, including supervising topic development at all stages of the writing and editing process, final review of all topics prior to publication, and direction of an internal team.

How to cite

National Library of Medicine, or "Vancouver style" (International Committee of Medical Journal Editors):

  • DynaMed [Internet]. Ipswich (MA): EBSCO Information Services. 1995 - . Record No. T114777, Orthostatic Hypotension and Orthostatic Syncope; [updated 2018 Nov 30, cited place cited date here]. Available from Registration and login required.

Published by EBSCO Information Services. Copyright © 2020, EBSCO Information Services. All rights reserved. No part of this may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission.

EBSCO Information Services accepts no liability for advice or information given herein or errors/omissions in the text. It is merely intended as a general informational overview of the subject for the healthcare professional.


Subscribe for unlimited access to DynaMed content.
Already subscribed? Sign in