Types of Long COVID
The long-term effects of COVID-19 are varied and can be serious. Terms such as “Long COVID” and “Post-COVID Syndrome” are used broadly, but actually refer to three distinct outcomes following infection:
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organ or tissue damage caused by the virus;
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a prolonged recovery period from the initial infection; or
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the development of an extended, potentially permanent, post-viral illness, such as or similar to Myalgic Encephalomyelitis (ME).
Each of these outcomes has different implications for care and recovery. Importantly, treatments that may benefit one group can harm another. For example, exercise-based approaches:
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may support recovery in cases of cardiac or organ-related injury, but
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can lead to significant—and potentially permanent—worsening of symptoms and function in individuals with post-viral illness involving Post-Exertional Malaise (PEM).
For this reason, it is essential to clearly distinguish between these different outcomes when discussing the long-term impacts of COVID-19, planning appropriate care, and conducting or interpreting research on Long COVID.
Read our think-piece: “Long COVID Is Not One Thing: Why Clear Definitions Matter for Care, Research, and Patient Safety”
Organ and tissue damage
Extended recovery time
Recovery from COVID-19 varies greatly among individuals:
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Mild cases may recover within 1-2 weeks5
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Severe cases can take 6 weeks or longer to recover5
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Some individuals experience symptoms lasting for months2
Recent research suggests that COVID-19 may linger in the body for 14 months to two years after infection, even after symptoms subside.2
Post-viral illnesses
For some patients, what their doctor has diagnosed as “Long COVID” shares many symptoms with Myalgic Encephalomyelitis (ME) (ref). ME can be triggered by various pathogens, including Epstein-Barr virus, Coxiella burnetii, and SARS-CoV-2 (the virus underlying COVID-19) (ref).
When Long-COVID persists and meets ME diagnostic criteria, it is essentially ME (ref). Recent studies show a significant overlap between this type of Long COVID diagnosis and an ME diagnosis after COVID-19, with 89% of post-COVID ME cases also meeting Long COVID criteria (ref, ref2).
Common symptoms of Long COVID/ME include:
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Fatigue
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Cognitive impairment ("brain fog")
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When triggered by COVID-19, symptoms may also include persistent cough and lung issues
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Autonomic dysfunction
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Post-exertional malaise (an immediate or delayed, sometimes severe, worsening of symptoms that may occur even after minimal physical, emotional, cognitive or sensory exertion).