This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
People with orthostatic intolerance may feel dizzy or weak when standing because of insufficient blood going to the brain and muscles. They may, as a result, have either a fast heartbeat or low blood pressure.
Researchers found that, compared with healthy volunteers, people with long COVID were more likely to have:
- previous symptoms of orthostatic intolerance
- symptoms such as dizziness or palpitations when standing up.
The researchers say people with long COVID would benefit from being tested for orthostatic intolerance.
The NHS website has more information on postural orthostatic tachycardia syndrome and postural hypotension.
The issue: how common is orthostatic intolerance in people with long COVID?
Symptoms of orthostatic intolerance can occur when someone is standing and their blood pools in the lower limbs. As a result, they may have either an increased heart rate (postural orthostatic tachycardia syndrome) or a drop in blood pressure (postural hypotension). Symptoms include dizziness, fainting, nausea, palpitations, tremors and weakness.
Studies suggest that many people with long COVID report symptoms of orthostatic intolerance. This study aimed to find out how common these symptoms are among people with long COVID.
What’s new?
The study included 277 adults with long COVID from 8 long COVID clinics across the UK. They were compared to 50 healthy volunteers of similar age and sex. Most (63%) were women and their average age was 48 years.
Participants were asked if they had experienced symptoms typical of orthostatic intolerance since contracting COVID-19. They also took a NASA (National Aeronautics and Space Administration) Lean Test at home or in the clinic. This test involves recording blood pressure, heart rate, and symptoms (of orthostatic intolerance) while lying down and then repeated at every minute of standing (against a wall) for up to 10 minutes.
The researchers found that many people with long COVID had:
- a history of symptoms of orthostatic intolerance (47%)
- symptoms of orthostatic intolerance during the lean test (52%)
- standing fast heartbeat during the lean test (7%).
None of the healthy volunteers had any of these signs or symptoms.
A similar proportion of people with long COVID (8%) and healthy volunteers (10%) had low blood pressure during the lean test. But while all of those with long COVID had symptoms, none of the healthy volunteers did.
Why is this important?
These findings confirm people with long COVID are more likely than others to have orthostatic intolerance, and that these problems are relatively common.
About half of the people with long COVID and orthostatic intolerance had symptoms. The researchers say that many symptoms of long COVID (such as dizziness, chest pain, palpitations and cognitive impairment) are similar to those of orthostatic intolerance. Clinicians could therefore consider performing the lean test on everyone with long COVID, regardless of their symptoms, they say.
What’s next?
As a result of this study, many long COVID clinics in the UK and elsewhere routinely carry out the lean test. The researchers say that everyone with long COVID, even those not attending clinics, would benefit from a lean test. It could ensure that they receive appropriate lifestyle advice and treatment, where necessary.
The study showed that the test can be performed at home; this could make its widespread use feasible.
This study was part of a larger study, LOCOMOTION, which aimed to identify the best way to treat and support people with long COVID. The team have produced a series of webinars presenting the findings of their studies.
You may be interested to read
This is a summary of: Lee C, and others. Prevalence of orthostatic intolerance in long covid clinic patients and healthy volunteers: A multicenter study. Journal of Medical Virology 2024; 96: 1 – 11.
Information and support for people with long COVID from The British Heart Foundation.
Information on checking people with long COVID for standing circulation problems: Espinosa-Gonzalez AB, and others. Orthostatic tachycardia after COVID-19. The British Medical Journal 2023; 230: e073488.
Information for GPs on caring for people with long COVID: Greenhalgh T, and others. Long covid—an update for primary care. The British Medical Journal 2022; 378: e072117.
Information on taking part in NIHR research on long COVID.
Funding: This study was funded by an NIHR long COVID grant.
Conflicts of Interest: None relevant.
Disclaimer: Summaries on NIHR Evidence are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that the views expressed are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the Department of Health and Social Care.
NIHR Evidence is covered by the creative commons, CC-BY licence. Written content and infographics may be freely reproduced provided that suitable acknowledgement is made. Note, this licence excludes comments and images made by third parties, audiovisual content, and linked content on other websites.
