5 Things to Know About Long COVID

Although a standardized definition has yet to be established, long COVID is generally considered the extended presence of post–COVID-19 or respiratory illness–related symptoms. These symptoms, like the definitions, vary by organization; however, authors of a recent study published in JAMA Network Open set out to compare lateral definitions and symptoms associated with long COVID and found 5 common symptoms among 5 comparator studies and the Innovative Support for Patients with SARS-CoV-2 Infections Registry (INSPIRE; NCT04610515) cohort.1 Yet, there were various discrepancies across all definitions, symptoms, patient inclusivity, and application to clinical practices.

Here are 5 things to know about long COVID related to definitions, clinical practices, and policy and research. | Image Credit: © blvdone-stock.adobe.com

Here are 5 things to know about long COVID, including symptoms, its impact on clinical practices, work and financial impairments, and policy.

1. A Call for a Standardized Definition

Because definitions vary so drastically, it is hard to pinpoint an exact number of people who may be currently experiencing long COVID or who are more susceptible to experiencing it. However, there were more than 100 million cases of SARS-CoV-2 infection in the US during the COVID-19 pandemic.1 As of August 12, 2025, the CDC estimated COVID-19 infections were growing or likely to grow in 34 states, with the highest probabilities for growth in Arizona, California, Mississippi, Tennessee, Texas, and South Carolina.

Regarding standing definitions, major organizations like the National Academies of Sciences, Engineering, and Medicine (NASEM) don’t require a COVID-19–positive laboratory test for patients to identify with long COVID symptoms. However, there are drawbacks to including COVID-19–negative individuals, as this may lead to an overdiagnosis of long COVID and underdiagnosis of other pressing respiratory illnesses with overlapping symptoms.

The American Journal of Managed Care® (AJMC®) spoke with Lauren Wisk, PhD, lead author of the study comparing lateral long COVID definitions. Wisk believed that the NASEM inclusion of COVID-19–negative individuals’ symptoms may stem from access to care. As COVID-19 tests rolled out, Wisk said that people who already had better access to care or were more “socioeconomically well-off” were more likely to have access to those tests first.

“Just in general, being able to get that diagnosis relies on going into a provider who has some sort of understanding or knowledge of both [COVID-19] and long COVID,” Wisk said in an interview with AJMC. “And I think [that is] very much wrapped up in the standard issue access problems that we have in the United States, where getting access to a high-quality provider in a timely fashion [is] not something that everybody can do, unfortunately.”

2. Clinical Burden: Long COVID Impairments

In Wisk’s study, the 5 common symptoms found in the INSPIRE cohort and the 5 comparator studies were:

• More tired than usual
• Pain or tightness in your chest
• Diarrhea (>3 loose or looser than normal stools in 24 hours)
• Decreased smell or change in smell
• Fatigue, tiredness, or exhaustion

The CDC also stated that people most likely susceptible to long COVID can be women, Hispanic and Latino people, people who have experienced more severe COVID-19 illness, those with underlying health issues, adults 65 years or older, and those who did not receive a COVID-19 vaccine.

Another study, led by Michael Gottlieb, MD—also published in JAMA Network Open—aimed to assess the work and financial impairments caused by self-reported long COVID patients. This study lists additional symptoms associated with long COVID specific to this study population as fatigue, dyspnea (shortness of breath), difficulty concentrating, and memory issues.2

Using the same INSPIRE cohort data, the study included 4119 US adults with COVID-19-like symptoms regardless of SARS-CoV-2 test results, 91.4% of whom reported at least 1 positive test since enrollment. Nearly all participants (3482 [95.1%]) received at least 1 COVID-19 vaccine, with most participants (2609 [71.2%]) reporting receiving 3 to 5 doses of a COVID-19 vaccine. Among participants, 27.1% (n = 994) reported current long COVID; these individuals were more likely to have reduced work hours, experience periods of unemployment, and attribute work loss to their symptoms when compared with individuals who reported never having long COVID (2604 [71.1%]) and those with resolved long COVID (65 [1.8%]).

The study authors noted that these findings “underscore the persistent and debilitating nature of long COVID,” as participants who reported ongoing long COVID symptoms had higher odds of experiencing worse rates of returning to work full-time and worse overall productivity, general activity impairment, and financial outcomes.2

“There is a need for more robust literature to better understand the influence of specific long COVID phenotypes on work and financial challenges, as well as interventions to both prevent and treat long COVID,” Gottlieb said in a written Q&A with AJMC. “Given the large number of people living with long COVID, as well as the persistence over time, we expect this to have a continued major economic impact on both individuals and society at large.”

3. Health System Impact

With ongoing research attempting to consolidate and rewrite a standard long COVID definition that reduces misdiagnosis, outpatient health care utilization has increased due to long COVID patients.3

A study published in BMC Public Health found that 17% of long COVID patients—out of a 26,358-person study population—were hospitalized at least once before being diagnosed with long COVID. They also saw that 40% visited the emergency department at least once on occasion. However, while utilization of acute health care, like hospitalizations and emergency department visits, decreased, outpatient services (office visits, specialist office visits, and new medication prescriptions) increased by an average of 4.5 percentage points. The study referenced recent reports documenting long COVID costs amounting to upwards of $3.7 trillion in health care spending and decreased productivity over the last 5 years.

The World Health Organization, in 2021, released an International Classification of Diseases, Tenth Revision (ICD-10) code for long COVID, which does not specify a length of time following COVID-19 diagnosis. However, once it was released, research showed inconsistencies in coding practices and adherence to the long COVID definition outlined in the ICD-10 code.4 

“Early identification and management of [long COVID] could play a critical role in alleviating the disease burden for both patients and the health care system,” the authors of the BMC Public Health study wrote.3

4. Treatment and Management Gaps

One of the distinguishing features between potential long COVID cases—among COVID-19 cases— and other respiratory-related illnesses is the number of symptoms present. Those with potential long COVID had a higher count of overall symptoms than those with other conditions. The self-reported nature of studies evaluating long COVID definitions creates a substantial differentiation in symptoms, in addition to a surplus number of overall symptoms to account for. In Wisk’s study, the list of symptoms used for defining long COVID across the 5 studies accounted for 24.8% to 32.9% of variation simply based on which symptoms each study chose to include. The NASEM definition is also even broader than those 5 studies because it also includes COVID-19–negative patient-reported symptoms.1

However, this is not without downsides, as the excess number of symptoms covered can potentially overcomplicate the diagnosis, reporting, and treatment of long COVID.

“If we don't have a good way to actually tell someone has long COVID, it's really hard to know if the current treatment protocols we've developed are going to do well for them,” Wisk said.

This cause for concern comes from potentially missing people who may have long COVID but may not meet a standard definition and overdiagnosing people whose symptoms may align with said definition but who don’t actually have long COVID.

“And if we're giving them a treatment for long COVID, we might be missing an opportunity to treat what's actually causing their symptoms,” Wisk explained. “I think both under- and overdiagnosis are potentially problematic here.”

On the other hand, Wisk also explained that while there are limitations and redundancies to collecting and basing data on self-reported symptoms, she said it is “the best that we’re going to get.” The self-reporting method for ascertaining the potential of symptoms for long COVID, Wisk says, is “fairly accurate at a given point in time”; however, when patients have to recall symptoms or how they felt from a month or 3 months ago, it’s harder for clinicians to obtain accurate reflections.

“It is crucial to establish a universally accepted definition of long COVID that is informed by comprehensive research and that is both sensitive and specific,” the study authors noted. “Without a validated, objective diagnostic tool to identify long COVID, most studies have relied on patients’ self-reported symptoms or those documented in the medical record to classify this condition.”1

5. Policy and Research Needs

More policy and research are needed to aid individuals who may be experiencing long COVID.

“We would encourage policies to help support those experiencing long COVID, including extended leave and workplace accommodations, including work from home and reduced hours,” Gottlieb wrote. “Most importantly, as long COVID affects individuals differently, we encourage employers to work with individuals to identify what accommodations can best meet their unique individual needs.”

In addition to the need for more robust literature, Gottlieb also encourages public health organizations to continue to advocate for resources and support for those who may be experiencing long COVID.

In 2022, the Biden administration launched a US government-wide response to long COVID to help direct federal efforts to identify the most immediate long COVID needs, but it did not describe the role of public health organizations addressing long COVID.The response addressed surveillance of the virus, primary prevention such as vaccination, and general public awareness, among other variables. 5

“An approach centered upon adaptability, humility, and engagement of multiple sectors may be needed to meaningfully support those affected,” the government response concluded. “Many people are in need, and there is much work to be done.”

References

1. Wisk LE, L’Hommedieu M, Diaz Roldan K, et al. Variability in long COVID definitions and validation of published prevalence rates. JAMA Netw Open. 2025;8(8):e2526506. doi:10.1001/jamanetworkopen.2025.26506

2. Gottlieb M, Chen J, Yu H, et al. Work impairment and financial outcomes among adults with vs without long COVID. JAMA Netw Open. 2025;8(8):e2526310. doi:10.1001/jamanetworkopen.2025.26310

3. DeVoss R, Carlton EJ, Jolley SE, Perraillon MC. Healthcare utilization patterns before and after a long COVID diagnosis: a case-control study. BMC Public Health. 2025;25(1):514. doi:10.1186/s12889-025-21393-4.

4. Zhang HG, Honerlaw JP, Maripuri M, et al. Potential pitfalls in the use of real-world data for studying long COVID. Nat Med. 2023;29(5):10401043.

5. Patel PR, Desai J, Plesica M, Baggett J, Briss P. The role of US public health agencies in addressing long COVID. Am J Prev Med. 2024;66(2):921-926. doi:10.1016/j.amepre.2024.01.004