Although COVID-19 is a potentially serious and life-threatening disease, the vast majority of people recover from infections relatively quickly. However, some individuals experience complications and side effects that can last weeks or even months after the initial illness.
Someone may be described as having post-Covid syndrome — also known as long Covid — if they have lingering health effects that persist for more than a month after the original infection. Although older adults and individuals with serious health conditions are more likely to develop post-Covid syndrome, young and otherwise healthy people can also fall victim to a range of distressing and debilitating symptoms.
What are post-Covid symptoms?
Experts are still learning about post-Covid, and there’s no universal definition of symptoms or how common these are.
In the United Kingdom, post-Covid refers to symptoms that persist for more than 12 weeks with no other potential causes. While in the United States, experts use a time frame of more than 4 weeks to describe the condition.
Symptoms may be vague and mild or severe enough to affect someone’s quality of life. In some cases, they can resolve, only to return later. Typically, long Covid signs slowly improve over time, but they could potentially last for years.
The most common long Covid symptoms include:
- Fatigue or extreme tiredness.
- Breathing difficulties such as shortness of breath.
- Chest pain or tightness.
- Heart palpitations.
- Tingling sensations.
- Dizziness and lightheadedness.
- Reduced or altered taste and smell.
- Memory and concentration problems.
- Joint pain.
- Digestive problems such as diarrhea or stomach pain.
- Sleeping difficulties.
- Vision changes.
- Skin rashes.
- Changes to menstrual cycles.
Some individuals may also experience new health conditions following COVID-19 illness. Because the disease affects many bodily systems, including the heart, lungs, kidneys, skin, and brain, people are more likely to develop conditions such as diabetes, heart problems, or neurological conditions.
What causes post-Covid?
As yet, experts don’t know why some people recover fully from COVID-19 with no residual symptoms while others develop post-Covid.
There are several theories, but none are confirmed. One reason could be that the initial COVID-19 infection triggers an extreme autoimmune reaction, where the immune system begins to attack healthy cells even after the body clears the virus.
It’s also possible that the virus damages cells and tissues as it replicates, leading to lingering symptoms. For example, if the virus damages the mucous membranes, it could contribute to loss of taste and smell, while if it affects the blood vessels, it could contribute to heart problems.
One study looked at nearly 800 brain images of people who had tested positive for SARS-CoV-2, the virus that causes COVID-19. They compared results with almost 400 control images of individuals who hadn’t tested positive. The researchers noted that COVID-19 infection appeared to cause slight brain shrinkage, particularly in areas connected to the sense of smell. These findings could explain the cognitive function and sensory changes that some individuals experience with long Covid.
Another small study found that some people with post-Covid syndrome had hidden lung damage, which scientists found using special gas to assess lung health rather than imaging studies alone. These results could explain the long-lasting breathlessness of many people with long Covid.
However, experts don’t currently understand the full significance of the changes seen in long Covid or if they’re permanent.
Who gets post-Covid syndrome, and is it common?
Although it may feel like the COVID-19 pandemic has lasted a lifetime, in terms of diseases, it’s relatively new, and experts still have a lot to learn. As a result, doctors have only recently begun recognizing and recording long Covid cases, and not many countries have published data.
In the UK, the Office for National Statistics estimates that around 1.5 million citizens have post-Covid syndrome. Around 4 in 10 of these individuals became infected with coronavirus at least 1 year earlier.
From personal data collected from people, it seems that long Covid is more common among:
- People aged 35 to 49.
- Those with underlying health conditions severe enough to limit activity.
- Individuals working in healthcare, social care, or education.
- People living in low-income areas.
- People with severe COVID-19, especially if hospitalized.
- Those with underlying health conditions.
- Unvaccinated individuals.
- Anyone who experienced multisystem inflammatory syndrome (MIS), a rare complication of Covid 19 that involves inflammation of the organs.
- People affected by health inequalities.
Is there a test for long Covid?
No, no test can tell if you have a long Covid. If someone has had COVID-19 and is experiencing lingering symptoms, their doctor must first rule out any other causes. They may check for health conditions such as diabetes, thyroid problems, or mineral deficiencies before considering a diagnosis of post-Covid syndrome.
There may be a blood test for long Covid in the future. However, there is a substantial amount of work to be done before doctors, experts, and scientists fully understand the condition.
Are there treatments for long Covid?
Currently, there is no single, proven medication to treat long Covid. Therefore, doctors focus on helping people cope with their symptoms and returning to their normal daily lives as soon as possible.
Everyone’s experience with COVID-19 is different, and people should discuss any long Covid symptoms with their doctor. Although there are no specific treatments, doctors can refer people to specialists or rehabilitation services who can help them manage as they recover.
Does vaccination reduce the risk of post-Covid syndrome?
Yes, there is evidence that the COVID-19 vaccination can reduce the likelihood of experiencing long Covid.
In a review of 15 long Covid studies from around the world, the authors found that fully vaccinated individuals who became ill with COVID-19 were 50% less likely to develop long Covid. Additionally, because vaccination reduces the risk of catching the SARS-CoV-2 virus, it significantly reduces the overall risk of developing long Covid.