Researchers from the Karolinska Institutet have identified increased odds of postural orthostatic tachycardia syndrome (POTS) in patients with long COVID, publishing their findings in Circulation: Arrhythmia and Electrophysiology on September 30, 2025.1
POTS was reported in approximately 1 in 3 patients with severe long COVID, vs under 1% of the general Swedish population prior to the COVID-19 pandemic. This highlighted a need to screen for POTS in patients with long COVID experiencing significant increases in heart rate while changing position from lying down to standing or during exertion.1
Key takeaways:
- Researchers from the Karolinska Institutet found POTS in approximately 31% of patients with severe long COVID.
- The condition was significantly more common in younger women, suggesting sex-specific vulnerability.
- Patients with POTS showed reduced physical activity and shorter walking distances during exercise tests.
- Simple, inexpensive tests such as the head-up tilt and Active Stand Test can help detect POTS in long COVID patients.
- A prior JAMA Internal Medicine study linked female sex, older age, and high BMI to increased long COVID risk.
“Previous, smaller studies have shown that there is a connection, but now we can say with certainty that POTS is a very common condition in patients with long COVID. This is valuable knowledge for both health care professionals and patients,” said Mikael Björnson, PhD student at the Karolinska Institutet.1
POTS evaluation
The study was conducted to evaluate the presence and clinical impact of POTS in long COVID patients.2 Highly symptomatic nonhospitalized long COVID patients were included in the analysis, with highly symptomatic defined as sick leave of 50% or greater.
Among this population, differences in demographics and clinical outcomes were compared between those with vs without POTS at a median 12 months following acute COVID-19 infection. Examinations included a 48-hour electrocardiogram, head-up tilt test, and Active Stand Test conducted by a cardiologist.2
There were 467 long COVID patients included in the final analysis, 31% of whom were diagnosed with POTS, 27% did not fulfill POTS criteria, and 42% did not present with clinical signs of POTS. Mean ages in these groups were 40, 44, and 47 years, respectively.2
POTS outcomes
A significant reduction in physical activity was reported in patients with POTS. This group also had an increased heart rate during the 6-minute walk test, both while walking and at rest after the walk.2
POTS patients had a significantly reduced walking distance during the 6-minute walk test vs those not fulfilling POTS criteria and not presenting with clinical signs of POTS, at 448 m, 472 m, and 509 m, respectively. However, no significant difference in the distribution of symptoms was observed between groups.2
These results indicated POTS is common among younger women with highly symptomatic long COVID. Investigators concluded POTS should be systematically assessed in women with this condition.2
“It is important to know that POTS can be detected with inexpensive, simple tests that are available at all levels of health care. For those who receive a diagnosis, there are treatments that can alleviate symptoms and improve quality of life,” said Judith Bruchfeld, PhD, associate professor at Karolinska Institutet.1
Female sex identified as a long COVID risk factor
These risks may be further increased by the association between female sex and long COVID risk, which was identified in a 2023 study published in JAMA Internal Medicine.3 Alongside female sex, the researchers identified links with long COVID for older age and certain clinical characteristics such as body mass index.
A 56% increase in long COVID risk was linked to female sex, with an odds ratio (OR) of 1.56. Additionally, patients aged 40 to 69 years and at least 70 years reported a significant increase in risk vs those aged 18 to 40 years, as did those with a high BMI. Odds ratios were:
- 1.56 for female sex
- 1.21 for older age
- 1.10 for BMI of 303 or greater
“Follow-up outpatient services may be needed to manage this condition and to better understand the possible association between symptoms and residual organ impairment,” wrote investigators.3
References
- POTS common in patients with long COVID. Karolinska Institutet. October 3, 2025. Accessed October 13, 2025. https://www.eurekalert.org/news-releases/1100722.
- Björnson M, Wijnbladh K, Törnberg A, et al. Prevalence and clinical impact of postural orthostatic tachycardia syndrome in highly symptomatic long COVID. Circulation: Arrhythmia and Electrophysiology. 2025. doi:10.1161/CIRCEP.124.013629
- Kunzmann K. Long COVID-19 risk linked to women, older age, higher BMI. Contemporary OB/GYN. March 27, 2023. Accessed October 13, 2025. https://www.contemporaryobgyn.net/view/long-covid-19-risk-linked-to-women-older-age-higher-bmi.
