COVID-19 has many, many strange side effects, alongside its usual symptoms. For example Covid Toe, occurrences of red-purple rashes and bumps on the toes. is a relatively common and harmless one.
The most notable and unpleasant occurrence is protracted or long-term COVID-19, where some symptoms (not always the same ones) don’t go away even after the infection is fought off and you are no longer contagious, persisting for months at a time. Relatively few people gain protracted symptoms, but we should still be interested as to why.
We are not sure what causes protracted COVID-19, though there are plenty of established risk factors. Obesity, high blood pressure, and old age are the predictable factors, but perfectly healthy people and even young kids can get protracted symptoms without meeting any risk criteria beforehand. In fact, it’s fairly common; about 20% of healthy people between the ages of 18 and 34, reported some persisting symptoms after infection. Some underlying health conditions also often correlate with increased risk of long-term symptoms. More bizarrely, mental health conditions are also risk factors which can increase your likelihood of retaining symptoms long-term; some people suspect that this is because continuously elevated stress levels increase blood pressure and damage your circulatory system, but that theory is not confirmed. Generally, stronger initial infection symptoms increase your likelihood of long-term symptoms.
The symptoms long-term COVID-19 are slightly different from the short term illness, and while you are less likely to actually die, there is significantly more long-term tissue damage. Because the virus likes
to infect circulatory lining as well as the respiratory system, long term symptoms include damage to heart and lung tissue, pain in joint muscles, and fatigue. Anosmia (loss of smell) is fairly common, as well as increased risk of damage from heart attacks or strokes. Other miscellaneous minor symptoms can also crop up, but are much more variable.
The strangest long term symptoms are mental health problems: anxiety, worsening post-traumatic
stress disorder, sleep disturbance, and most notably depression have been recorded and correlated with COVID-19. In fact, 4 months post-infection, 52% of patients met criteria for major depression. Greater severity of depressive symptoms was associated with having headaches during infection and perceived high severity of infection. Older people were also more likely to feel depressive symptoms.
Why does COVID-19 seem to cause or worsen depression and other mental health problems? We’re not sure, but it’s probably a complicated answer. It is entirely possible that these symptoms are a consequence of central nervous system damage from infection. However, the social disruption following infection, or the patient’s own psychological reaction to infection could certainly play a major role as well. Feeling frequently uncomfortable or in pain, combined with potential difficulty sleeping probably also has some negative psychological effects. Ultimately, there have only been a few studies done on the mental health effects of COVID-19. Determining the cause of mental health problems is very difficult; this is why medicine must consider not only the physical, but the social symptoms of disease.