

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).
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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
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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).
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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).

