Most people who contract COVID-19 do not become severely ill, and they get over the symptoms relatively quickly. Occasionally, it’s possible for some symptoms to persist for months on end, even if the person didn’t get very ill. In fact, new research from the World Health Organization (WHO) identifies residual symptoms as long COVID, which is more common than health experts originally thought.
On October 6th, 2021, the WHO announced the official definition of long COVID. The medical community acknowledges that some people experience lingering symptoms for four or more weeks after developing COVID-19. There has not been a formal definition for this phenomenon until now, which may or may not require hospitalization. Many of the long-term effects include brain fog, respiratory symptoms, and fatigue.
What Is Long COVID?
Long COVID refers to people who continue to experience symptoms of COVID-19. This includes people who do not fully recover for several weeks or months after initial symptoms. In the past, some researchers described this phenomenon as post-COVID-19 condition, but now long COVID is the official name. The symptoms can range from mild to severe, and they can’t be explained by any other cause than COVID-19 development. Although surveys identified tens or even hundreds of symptoms, the most common ones are:
- Changes in taste or smell
- Extreme fatigue
- Problems with memory or concentration (brain fog)
- Shortness of breath
- Chest pain or heart palpitations
- Joint pain
What Causes Long COVID?
At this point in time, health experts do not know what causes long COVID. A possible theory is that the infection makes certain people’s immune systems kick into overdrive. At that point, the immune system attacks not only the virus, but also the body’s own tissues. This can happen in people who have powerful immune responses. The virus gets into the cells and can cause damage, which may explain the lingering symptoms, according to medical professionals. Cell damage can lead to brain fog or loss of taste/smell, whereas blood vessel damage can lead to long-term heart, brain, and lung problems.
Another potential theory is that fragments of the virus remain dormant in the body, becoming reactivated at a later point in time. This is common in other viruses, including the Epstein Barr virus or the herpes virus. There isn’t much evidence for this happening with COVID-19, though. The assumption is that there are several contributing factors, but it also has to do with each person’s internal activity.
Prevalence Of Long COVID
A 2020 survey by the Centers for Disease Control and Prevention (CDC) suggests that it can take weeks to overcome COVID-19 symptoms. It’s possible for young and old adults, and for people with no chronic medical conditions, to return to their usual state of health. To put it in perspective, about 90% of people discharged from the hospital with influenza generally recover within two weeks.
As time goes on, more and more evidence suggests that people who contract SARS-CoV-2 continue to experience COVID-19 symptoms. The amount of people who experience these prolonged symptoms is still unclear. Data from the COVID Symptoms Study app, however, suggests that one in 10 people with COVID-19 experiences symptoms for three weeks or longer. Similar results were found in data from the United Kingdom’s Office for National Statistics. That means that there may be more than five million cases of long COVID at this time.
There is no test to diagnose long COVID. Medical experts say that the diagnosis is based on exclusion, ruling out all possible causes for the symptoms that each person experiences. Before concluding the diagnosis to be long COVID, doctors rule out things like diabetes, thyroid dysfunction, and even iron deficiency. A blood test for long COVID may become available in the future, and more sophisticated tools currently exist in research settings.