One of the revelations from the COVID pandemic is that people can suffer debilitating symptoms long after they have recovered from the acute infection. Long COVID affects tens of millions of people who report long-lasting problems for months or even years after the initial illness. Doctors refer to this condition as postacute sequelae of SARS-CoV-2 infection (PASC). They call it a number of other names, as well. Now, scientists report that other respiratory infections can also cause persistent symptoms (eClinicalMedicine,October 6, 2023). In some cases, these are similar to symptoms of long COVID, such as fatigue, shortness of breath, digestive distress and brain fog.
How Common Are Symptoms That Persist After COVID?
By now, it’s clear that eople who experience a COVID infection run the risk of lingering symptoms. They may suffer from fatigue and postexertional malaise, in particular. These problems sometimes persist for months or sometimes longer after an individual has otherwise recovered.
Danish researchers wondered how common these symptoms are, so they undertook a study of more than 50,000 adults (JAMA Network Open, Oct. 7, 2024). At several intervals, volunteers responded to online questionnaires that covered fatigue and COVID-19 test results.
People who reported a positive COVID test had a 3 percent higher likelihood of fatigue over the next year and a half. They were also twice as likely as those without COVID infection to experience postexertional malaise. That small increase in fatigue was statistically significant. People with more serious infections had a more dramatic 23 percent increase in their chance of fatigue in the 2 to 18 months following discharge. The number of people suffering severe fatigue was higher soon after the infection and decreased over time.
The investigators conclude,
“SARS-CoV-2 infection was associated with a subtle increase in the risk of postacute fatigue and [post-exertional malaise] 2 to 18 months after mild infection.”
Lingering Problems After Respiratory Infections:
Some experts suspect that the inflammation the immune system musters to overcome an infection may be the source of such symptoms. There are differences among viruses, though. Trouble with the senses of smell and taste are especially common and severe with long COVID. People suffering after COVID-19 infections also reported hair loss, unusual sweating, rapid heart rate and memory problems. These symptoms were less likely to appear in reports after other infections. Human metapneumovirus, on the other hand, can often lead to a cough that lasts for a long time.
For years, people who experienced lasting, debilitating fatigue following an infection were not taken very seriously. Now, thanks to long COVID, doctors are starting to recognize that a variety of viral infections can trigger long-lasting symptoms.
The investigators conclude
“The COVID-19 pandemic has cast a much-needed spotlight on post-acute infection syndromes, highlighting the need for improved understanding, diagnosis, and treatment of these conditions.”
Common Symptoms of Long COVID:
A study published in JAMA offered a more manageable list with a strong connection to long COVID (JAMA, May 25, 2023). Investigators for RECOVER recruited 9,764 people, most of whom had been diagnosed with COVID previously. Those with long COVID were still suffering after six months or more.
They were more likely to report one of the following symptoms: postexertional malaise, fatigue, dizziness, brain fog and gastrointestinal problems. Postexertional malaise refers to worsening symptoms following even minor physical or mental exertion. Physicians have seen this previously among individuals with chronic fatigue syndrome/myalgic encephalomyelitis. Such postexertional malaise takes a huge toll on people’s ability to work or even live normal lives. In total, 12 symptoms were significantly more common among those with long COVID.
They include:
- alterations/loss of smell and/or taste
- postexertional malaise
- chronic cough
- brain fog
- thirst
- palpitations
- chest pain
- fatigue
- reduced sexual desire or capacity
- dizziness
- gastrointestinal complaints
- abnormal movements
The researchers weighted these to develop a score that would identify long COVID. Overall, approximately 23 percent of the participants who had experienced infection were identified as having long COVID. That makes long COVID itself a distressingly common complication.
High Blood Pressure as a Result of Long COVID:
In a separate study, researchers report that people with no previous blood pressure problems are more likely to develop hypertension after a attack of COVID-19 (Hypertension, Aug. 21, 2023). The investigators reviewed over 45,000 medical records of patients who had COVID and nearly 14,000 records of individuals who had influenza.
Six months after infection, the people who were hospitalized with COVID were more than twice as likely to have persistent high blood pressure as those who had recovered from influenza. Even people who were not hospitalized were one and a half times more likely to have lingering hypertension than those who had come down with the flu. One fifth of the people who were hospitalized with SARS-CoV-2 developed lasting hypertension, even though their blood pressure had been normal prior to COVID. As a result, we should add hypertension to the symptoms of long COVID.
Previous Research on Symptoms of Long COVID:
The report in JAMA is not the only in-depth exploration of the symptoms of long COVID. An earlier review article was a collaborative effort between individuals with the Patient-Led Research Collaborative and the Scripps Research Translational Institute. They published their extensive overview in Nature Reviews Microbiology (Jan. 13, 2023, updated April 17, 2023). The authors (including two people who themselves have long COVID) point out that rates of long COVID are highest (50% or higher) among patients who were hospitalized. Nonetheless, most of the cases are among people who had mild cases of COVID initially. That is because huge numbers of people experienced such infections.
Figure 1 in this paper is a simple and elegant collation of symptoms with known pathology. We strongly recommend viewing it. The 18 symptoms that these authors identify overlap with those named by the RECOVER researchers. However, reproductive system effects and problems such as new-onset diabetes deserve special attention.
What About Treatment?
So far, investigators have not found treatments that cure long COVID. However, there are some strategies to ease the symptoms. People with postural orthostatic tachycardia syndrome (POTS) may feel better if they take a beta-blocker drug to regulate heart rate. Those with brain fog sometimes find low-dose naltrexone helpful. Anticoagulants hold promise because clotting is part of the clinical picture. Exercise, on the other hand, generally worsens the symptoms of long COVID and should not be recommended as a treatment. Supplements such as D-ribose and CoQ10 need further study.
Learn More:
Many of the links in this article will take you to one of our interviews for The People’s Pharmacy podcast. You may find Show 1392: Grappling with the Mysteries of Long COVID to be especially relevant. We’d also like to suggest this conversation between Dr. Eric Topol and one of the co-authors of the Nature Reviews Microbiology paper, Hannah Davis. Dr. Topol posted it on Ground Truths, his Substack platform, on 6/6/2023.
