strange symptoms of covid: 'nothing is off the table'

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from covid toes to covid tongue and everything in between, the virus is wreaking havoc on survivors.

by dave yasvinski

published mar 19, 2021

last updated feb 24, 2025

5 minute read

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5 minute read

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the strange symptoms of covid-19: 'nothing is off the table'

covid-19 infections come with a whole host of different symptoms. getty

as the pandemic painfully plods into its second year, it often feels like the more we learn about the virus, the less we actually know. while most people are aware that a dry cough, fever and fatigue are telltale signs of covid-19, the more elusive symptoms are like a box of chocolates: you never know what you’re going to get.

for patients unfortunate enough to develop the more mysterious manifestations of the disease, it can be a frustrating experience. “really, nothing is off the table when it comes to covid,” said joseph khabbaza, a pulmonary and critical care physician at the cleveland clinic. “i always get texts from people asking if something they’re experiencing is normal. well, there’s nothing that’s truly abnormal when it comes to covid — literally almost anything goes and we don’t exactly know why.”

here are some of the more puzzling ways the pandemic plays havoc with the human body and the best guesses as to why they happen.

hallucinations, delirium and brain fog

brain fog has been gaining more attention as a lingering symptom plaguing long haulers — the term used to describe the roughly 10 per cent of covid sufferers who endure prolonged symptoms of the virus months after they were infected. like delirium and hallucinations, the symptom is most likely the result of the fierce battle the body’s immune system is waging against the virus.

“brain fog is kind of a big one,” khabbaza said. “it’s a kind of mental cloudiness — like you’re in a daze. “you hear a lot about it with mild outpatients, but we also see it more severely in the icu. hallucinations and confusion are commonly experienced during all sorts of severe illnesses. when you have a kind stressor like covid-19 in the body, you’re more likely to be confused, especially if you are elderly. this symptom is very common with older people as the body is trying to fight off an infection.”

some of the medication hospitals use to keep patients comfortable while on ventilators may contribute to these symptoms, he said. as a patient’s condition worsens, so too do these symptoms. “this can be due to a combination of blood flow and inflammation in the body or potentially alterations in blood flow at the microvascular level that cause these reactions.”

spiking heart rate or body temperature

the slightest amount of physical activity can send some patients into overdrive. a rapidly rising heart rate, easily confused with other conditions, is believed to be the result of the body’s autonomic nervous system not working properly. “we’re seeing this more and more,” khabbaza said. “when it occurs, our immune system is attacking autonomic nerves — so nerves that regulate things in the body like heart rate and temperature — that thermostat can be thrown off. when this occurs, people’s heart rates are not being regulated.

“once you lose that balance, you can have a super-high heart rate or elevated temperature for no reason. we’ve seen that in a lot of people and it seems to be an immune-mediated response, meaning the antibodies that you make somehow attack these kinds of nerves.”

blood clots

some studies have found that around 30 per cent of extreme covid cases involve clotting complications, according to the aarp. alex spyropoulos, a clot specialist at the donald and barbara zucker school of medicine in new york, said as many as 40 per cent of patients hospitalized by the virus die from blood clots or the damage they inflict on the body. the symptom may be the result of the virus interfering with clotting pathways or triggering a hyperimmune response, but doctors still aren’t sure. “the risk of blood clots is anywhere from about three- to sixfold or greater, more than we’re used to seeing,” he said. “it has us all in the academic community a little bit befuddled, because it’s one of the most aggressive diseases with respect to blood clots that we’ve ever seen.”

covid toes, covid tongues and other skin irritations

one peculiar symptom, which turns toes red and purple and results in a burning, itching sensation, isn’t all that uncommon when dealing with a virus, khabbaza said. “when you think about it, anywhere where blood flows could be affected,” he said. “skin is the body’s largest organ so it has the most blood vessels. it’s natural to see manifestations of illness in our skin. a lot of autoimmune diseases, in general, are associated with skin manifestations, especially viruses.”

this includes the tongue, which, in some covid patients who develop lesions on their tongue and like ‘covid toes,’ may experience a burning sensation.

people experiencing these, or other skin issues, generally don’t have other symptoms or require hospitalization and the symptoms gradually recede with time.

diarrhea, vomiting and loss of appetite

around one-third of patients in a stanford university study endured mild gastrointestinal problems as a result of the covid-19 and the cdc has included such symptoms on its virus watchlist. “there’s no question at this point that gi symptoms can be a manifestation of covid-19,” said william chey, a professor of gastroenterology and nutrition sciences at the university of michigan. while the cause of the tummy turmoil remains mostly unknown, the virus is able to directly attack the cells lining the gi tract, chey said. the symptoms could also be fallout from the body’s battle with the virus elsewhere. he recommends disinfecting surfaces often. “this whole issue about meticulous hand hygiene is so unbelievably important,” he said. “people need to wash their hands and not touch their face.”

loss of taste or smell

although alarming for obvious reasons, khabbaza said the disappearance of two of your five senses is just a temporary side effect of your body battling the virus. “when this occurs, those senses are just not working normally. nerves can be inflamed or secondarily irritated by our own immune system. but gradually with time, we should gain the ability to use them again.”

some covid survivors experience phantosmia, or parosmia — smelling smells that aren’t actually there, like vinegar, rotting food, smoke, even feces.

“the cells in your nose that are normally responding to odors, which are specialized nerve cells, are somehow not functioning properly and sending an incorrect signal back to the brain,” dr. steven munger, the director of the university of florida center for smell and taste, told wink news.

if you experience any of these unusual symptoms, khabbaza said there is no reason to panic but medical attention should be sought if they begin to interfere with your life.

“most things are going to run their course and should gradually improve, but it can be a very slow process,” he said. “if anything occurring is significantly affecting your daily living, your healthcare provider needs to know about it. there may not always be some intervention that can be done, but covid changes every day. we learn more every day and there are so many moving parts.

“if you’re having difficulty, you always want to make sure your healthcare provider is aware of everything.”

dave yasvinski is a writer with healthing.ca

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