Coronavirus (COVID-19) can cause symptoms that last weeks or months after the infection have gone in some people. This is sometimes called “long COVID” or post-COVID-19 syndrome. They commonly experience: tiredness or fatigue worsened after physical or mental activities (post-exertional malaise); difficulty in thinking or concentrating (“brain fog”); cough; chest or stomach pain; headache; fast-beating or pounding heart (heart palpitations); pins-and-needles feeling; diarrhea; sleep problems; fever; dizziness on standing (lightheadedness); rash; mood changes; smell or taste change; menstrual period cycles changes.
“Post-COVID syndrome” is an umbrella term that includes a wide range of physical and mental health problems occurring four or more weeks after SARS-CoV-2 infection . Long-term COVID-19 symptoms have been referred to by The National Institutes of Health as post-acute sequelae of SARS-CoV-2 (PASC). Common terms are long COVID or long-term COVID. People with post-COVID syndrome are sometimes known as “long haulers” . In October 2021, WHO defined long COVID as persistent or fluctuating symptoms with an impact on everyday function following history or probable history of SARS-CoV-2 infection that last for at least 2 months and cannot be explained by an alternative diagnosis in adults. However, the definition has not yet been specified for children or adolescents .
Long-term COVID-19 symptoms can occur in some COVID-19 infected patients including those with initial mild or asymptomatic acute infection . The condition seems to be more common in women than in men (23% of women and 19% of men had symptoms 5 weeks after infection). There is also a distinctive age distribution. Long COVID is most common in middle-aged people (25.6% at 5 weeks in patients between 35 and 49 years old). It is less common in younger and older people. This age distribution pattern may probably be explained by ‘survivor bias’. About 9.8% of children aged 2–11, who are virus positive, still have symptoms after at least 5 weeks . It’s not known whether COVID-19 infected children are more or less likely than adults to experience continuing symptoms . Those who had positive COVID-19 PCR tests are more likely to have long-COVID symptoms than those with a negative test result — and were almost twice as likely to report three or more symptoms . There isn’t a clear link between certain risk factors (including high blood pressure, smoking, diabetes, obesity and other) and long-term problems . A team at University College London found 205 symptoms in a study of more than 3,500 people with long COVID. By month 6, the most common symptoms were “fatigue, postexertional malaise, and cognitive dysfunction” . Long-term COVID-19 in children is shown up as fatigue, depression, shortness of breath and other long-hauler symptoms . The persistence of these health problems in some people could be due to organ damage, a persistent inflammatory or autoimmune response or another reason .
According to the CDC, the most common lasting symptoms are fatigue, shortness of breath, cough, joint pain and chest pain. Other issues include cognitive problems, difficulty concentrating, depression, muscle pain, headache, rapid heartbeat, and intermittent fever. They occur in different combinations and last for weeks or months even in COVID-19 infected person with mild illness or no initial symptoms .
Multiorgan Effects of COVID-19
Some people with severe COVID-19 experience multiorgan
effects or autoimmune conditions for weeks or months after
COVID-19 illness. Multiorgan effects can affect many, or all, body
systems, including heart, lung, kidney, skin, and brain functions.
Some people, mostly children, experience very rarely multisystem
inflammatory syndrome (MIS) during or immediately after a
COVID-19 infection .
Effects of COVID-19 Illness or Hospitalization
Hospitalizations including post-intensive care admission
for severe COVID-19 can cause severe weakness and exhaustion
during the recovery period. Other effects include problems
with thinking and judgment, and post-traumatic stress disorder
The best way to prevent post-COVID conditions is to prevent
COVID-19 illness. For eligible people, vaccination against
COVID-19 has to be given as soon as possible .
The disease mechanisms causing long COVID are unknown,
and there are no evidence-based treatment options. Clinical
guidelines focus on symptom management, and various treatment
options are being evaluated .
What about the impact of vaccines in people who already
have long COVID?
A UK survey of more than 800 people with long COVID,
reported an overall improvement in their symptoms in 57% of cases, no change in 24% of cases and deterioration in 19% of cases after their first dose of vaccine. The vaccine might improve
symptoms by eliminating any virus or viral remnants left in the
body, or by rebalancing the immune system .
Understanding of post-COVID conditions remains incomplete.
It seems unlikely that there is a single explanation for long
COVID. Several mechanisms are likely at work, and guidance for
healthcare professionals will likely change over time as evidence