COVID-19 affects different individuals in different ways. Some people experience minor symptoms or none at all, while others develop long-term, debilitating symptoms and suffer organ damage. As time progresses, knowledge about COVID-19 continues to evolve. The following is some of what we currently know about COVID-19, how it affects the body, and how that might contribute to long-term symptoms.

What is Post-COVID Syndrome?

Post-COVID syndrome is a wide range of new, returning, or ongoing health problems that some individuals experience four or more weeks after first being infected with SARS-CoV-2, the virus that causes COVID-19.1 

The condition is known by several names. The National Institutes of Health refers to long-term COVID-19 symptoms as post-acute sequelae of SARS-CoV-2 (PASC). More common terms are post-COVID syndrome, long COVID, and long-term or long-haul COVID. Individuals living with post-COVID syndrome are often called “long haulers.”1

People with long COVID no longer have live coronavirus in their bodies. If tested, they would produce a negative result, and they are no longer infectious.

Symptoms of Post-COVID Syndrome 

Post-COVID syndrome is more than a group of symptoms. It is a condition that can greatly affect a person’s quality of life, functionality, and activities of daily living. Although there is no universally accepted definition or diagnostic criteria for long COVID, certain symptoms often occur. 

According to the Centers for Disease Control and Prevention (CDC), the most common lasting symptoms are fatigue, shortness of breath, cough, joint pain, and chest pain.1 Other common issues include cognitive problems (often called brain fog), loss of smell or taste, difficulty concentrating, depression, anxiety, muscle pain, headache, rapid heartbeat, dizziness/lightheadedness, restless sleep, numbness/tingling sensations, and temperature dysregulation.1,2 

Symptoms can last for weeks, months, or years and range from mild to debilitating. For example, some individuals might experience a slight shortness of breath, while others need to remain on oxygen for several months after they are no longer infectious. Some people have sustained damage to their lungs, heart, kidneys, brain, or other organs. Individuals with debilitating symptoms of long COVID have lost their jobs and often lack the energy to do common activities like taking a shower.1,2  

Who is Likely to Get Post-COVID Syndrome?

Current estimates indicate that 10-20 percent of individuals who become infected with COVID-19 develop long COVID.3 Long-term symptoms can develop in anyone who had COVID-19, regardless of the severity of their initial infection. In other words, post-COVID syndrome can occur in thoselove  who had a severe case of COVID-19, a mild case, or were even asymptomatic. In addition, neither the severity nor the duration of long COVID symptoms correlate with the severity of COVID-19 infection.1 

Because the highly contagious Omicron variant infected millions of people, it stands to reason that millions of people could develop long-COVID. At this point, however, it's too early to tell. Researchers around the world are working to uncover why long COVID develops in some people but not in others.

A recent study identified four factors that might predict if a person will develop long COVID. One factor is the presence of autoantibodies – antibodies that attack the body's own tissues as seen in conditions like rheumatoid arthritis. Another factor is the level of coronavirus RNA in the blood while an individual is infected with COVID-19. A third factor is the reactivation of the Epstein-Barr virus in the body – a virus that infects people but then becomes dormant. The fourth factor is having type 2 diabetes.4 Although more research is needed, experts hypothesize that diabetes is only one of several medical conditions that might increase the risk of long COVID.

Although vaccines reduce the risk of developing serious illness from COVID-19 (hospitalization and death), it's unknown at this time if vaccines provide protection from long COVID. Current studies that have examined this concept have produced mixed results. More time and data are needed before scientists can determine if vaccines reduce the risk of long COVID.

How SARS-COV-2 Affects the Body in Post-COVID Syndrome

Researchers are just scratching the surface in learning how the SARS-COV-2 virus produces biochemical changes in the body. The National Institutes of Health announced that it will spend $1.15 billion over the next four years to study these effects.5 

The following is what we currently know about how the SARS-COV-2 virus affects the body and how it might contribute to symptoms of long COVID. 

The Lungs. COVID-19 can produce scarring and other permanent problems in the lungs. In addition, the body responds to the virus by creating inflammation. In some individuals with COVID-19, inflammation can go into overdrive. Too much inflammation can further damage the lungs and other organs. Research is revealing how COVID-19 damages blood vessels in the lungs and can trigger clots, which helps explain how it impairs breathing and causes long-term damage and symptoms.6 

The Brain and Nervous System. Many of the neurological symptoms of long COVID (dizziness, headache, cognitive issues, chronic fatigue, depression, and anxiety) are likely a result of the body’s widespread immune response to infection rather than the virus directly infecting the brain or nervous system.7 

Researchers in Italy performed brain magnetic resonance imaging (MRI) on 50 patients with post COVID syndrome8 and found that many of them showed a decreased volume of gray matter in the brain and changes in microstructure. These findings are similar to the brains of individuals who suffer from anxiety, depression, chronic pain, and chronic fatigue. 

The brain changes were directly related to the amount of inflammation a patient experienced during their SARS-COV-2 infection. In other words, patients who had increased markers of inflammation while they were initially sick showed more pronounced changes on the MRI and worse health symptoms. 

The Heart. Imaging tests taken months after recovery from COVID-19 show that some individuals have lasting damage to the heart, including those who experienced only mild symptoms.9,10 Too much inflammation can damage the heart and disrupt the electrical signals that enable it to beat properly. This reduces the heart's ability to pump properly and can lead to palpitations and abnormal heart rhythms, called arrhythmias.11 

A recent study found that individuals who recovered from COVID-19 were 63-percent more likely to have had a cardiovascular event in the ensuing year than individuals in the control groups who didn't contract COVID-19.12 Specifically, that includes a 52-percent greater likelihood of having a stroke, a 72-percent higher likelihood of heart failure, and a 63-percent higher likelihood of a heart attack. These risk factors increased regardless of age, race, sex, obesity, smoking, or other cardiovascular disease risk factors.

Researchers are also reporting new evidence from laboratory studies that the SARS-CoV-2 virus might directly infect heart cells, changing their ability to function after just 72 hours. These results might provide insight on future pathways to counteract heart damage caused by COVID-19.13    

Blood Clots and Blood Vessel Problems. COVID-19 can make blood cells more likely to clump and form clots. Although large clots can cause heart attacks and strokes, other parts of the body affected by blood clots include the lungs, legs, liver, and kidneys. COVID-19 can also weaken blood vessels and cause them to leak, which contributes to potentially long-lasting problems with the liver and kidneys.9,13,14

Treatments and Hope for Post-COVID Syndrome 

Researchers are recommending that healthcare professionals monitor people who have had COVID-19 to determine how their organs are functioning after recovery. In addition, many large medical centers are opening specialized clinics to provide care for those who have persistent symptoms or illnesses related to COVID-19. 

At Mayo Clinic’s COVID Activity Rehabilitation Program, a team of physicians, nurses, and health and wellness specialists provide coordinated care to help individuals who are struggling with long COVID. Greg Vanichkachorn, M.D., Medical Director of the COVID Activity Rehabilitation Program, explains that the medical field is presently in "an adapt and manage scenario" of treating long COVID symptoms. He and the team have developed programs and self-management tools that can decrease post-COVID symptoms and improve overall functioning and quality of life. To qualify for the program, patients must meet the following criteria: 

  1. A positive antigen or PCR test within 1-3 months
  2. Be 18 years old or older
  3. Be employed
  4. Reside within Minnesota
  5. Provide the name of a local primary care provider who will partner with Mayo Clinic experts

Another Mayo Clinic program, called the Post-COVID Care Clinic, offers online support, a blog, and information for individuals with long COVID who don't qualify for the rehabilitation program.

Dr. Vanichkachorn is optimistic that research will lead to effective treatments for patients who are experiencing long COVID symptoms, possibly even preventing the condition in the first place. In the meantime, he encourages patients to get help if they need it. 

Much is still unknown about how COVID-19 will affect the body over time. The best way to prevent developing long COVID is to not get COVID-19. And the best ways to avoid COVID-19 are to get vaccinated and continue hygiene precautions like social distancing, hand sanitizing, and masking.

References

  1. Post-COVID conditions. Centers for Disease Control and Preventions. https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects/index.html. [Accessed March 11, 2022]
  2. Vanichkachorn G, Newcomb R, Cowl CT, et al. Post-COVID-19 syndrome (long haul syndrome): description of a multidisciplinary clinic at Mayo Clinic and characteristics of the initial patient cohort. Mayo Clin Proc 2021;96(7):1782-1791.
  3. Logue JK, Franko NM, McCulloch DJ, et al. Sequelae in adults at 6 months after COVID-19 infection. JAMA Netw Open 2021;4(2):e210830. 
  4. Su Y, Yuan D, Chen DG, et al. Multiple early factors anticipate post-acute COVID-19 sequelae. Cell 2022;185(5):881-895.e20. 
  5. NIH launches new initiative to study "long COVID." National Institutes of Health. https://www.nih.gov/about-nih/who-we-are/nih-director/statements/nih-launches-new-initiative-study-long-covid. [Accessed March 12, 2022]
  6. Ackermann M, Verleden SE, Kuehnel M, et al. Pulmonary vascular endothelialitis, thrombosis, and angiogenesis in COVID-19. N Engl J Med 2020;383(2):120-128. 
  7. Pero A, Ng S, Cai D. COVID-19: a perspective from clinical neurology and neuroscience. Neuroscientist 2020;26(5-6):387-391.
  8. Benedetti F, Palladini M, Paolini M, et al. Brain correlates of depression, post-traumatic distress, and inflammatory biomarkers in COVID-19 survivors: a multimodal magnetic resonance imaging study. Brain Behav Immun Health 2021;18:100387. 
  9. Puntmann VO, Carerj ML, Wieters I, et al. Outcomes of cardiovascular magnetic resonance imaging in patients recently recovered from coronavirus disease 2019 (COVID-19) [published correction appears in JAMA Cardiol 2020;5(11):1308]. JAMA Cardiol. 2020;5(11):1265-1273. 
  10. Yancy CW, Fonarow GC. Coronavirus disease 2019 (COVID-19) and the heart – is heart failure the next chapter? JAMA Cardiol 2020;5(11):1216-1217.
  11. COVID-19 and the heart. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/coronavirus/heart#:~:text=SARS%2DCoV%2D2,oxygen%20to%20other%20tissues. [Accessed March 11, 2022]
  12. Xie Y, Xu E, Bowe B, Al-Aly Z. Long-term cardiovascular outcomes of COVID-19. Nat Med 2022;28(3):583-590. 
  13. Sharma A, Garcia G Jr, Wang Y, et al. Human iPSC-Derived cardiomyocytes are susceptible to SARS-CoV-2 infection. Cell Rep Med 2020;1(4):100052.
  14. Mitrani RD, Dabas N, Goldberger JJ. COVID-19 cardiac injury: implications for long-term surveillance and outcomes in survivors. Heart Rhythm+ 2020;17(11):1984-1990.