11 Troubling New Covid-19 Symptoms and Complications

Updated: Jul. 18, 2022

The CDC and healthcare workers report new Covid-19 symptoms, ranging from the loss of taste or smell to "Covid toes."

New Covid-19 symptoms

New symptoms of Covid-19 seem to appear every day. In May 2020, the Centers for Disease Control and Prevention’s (CDC) list grew six. But even the CDC definition doesn’t include the entire spectrum of symptoms healthcare workers are seeing, says William Schaffner, MD, an infectious diseases specialist at Vanderbilt University Medical Center in Nashville. The main symptoms of Covid-19 are still mainly respiratory—cough and shortness of breath, along with a fever—but it doesn’t stop there.

“There’s a profound inflammatory response going on everywhere in the body,” explains Matthew G. Heinz, MD, a hospitalist and internist at Tucson Medical Center in Arizona. “It’s not just affecting one particular organ system.”

Signs of Covid-19 are appearing all over the body. Because the virus is so new, research is still preliminary, but this is what is known so far about some of the more troubling symptoms and complications.

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Loss of smell or taste

This symptom appears on the updated CDC list of Covid-19 symptoms. It also happens with some other viruses, says Aaron Glatt, MD, a spokesperson for the Infectious Diseases Society of America, but more so with the new coronavirus.

Several studies have documented this, including one published in April 2020 in the International Forum of Allergy & Rhinology (IFAR), which found that 68 percent of Covid-19 patients (40 out of the 59) reported losing their sense of smell (known as anosmia). A total of 71 percent reported no taste, as compared with 16 percent and 17 percent of people who had tested negative. The symptom tends to appear early in the disease, says Dr. Heinz, and patients tend to be younger, according to an April 2020 study published in the European Journal of Neurology. The good news, according to another April 2020 study in the IFAR, is that people who lose their sense of taste and smell often have milder illness. (Here’s why Covid-19 causes a loss of smell.)

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“Covid toes”

This symptom looks a lot like chilblains, which is redness, swelling, and itching of the toes (or fingers) in cold weather. Unlike chilblains, though, Covid toes are occurring in warmer weather, notes an April 2020 report in the Journal of the American Academy of Dermatology. Like losing your sense of taste and smell, Covid toes seem to be an early symptom of the virus. And, says Dr. Heinz, “is associated with milder symptoms or may be the only symptom.” It also tends to appear in younger people. It’s not clear what causes this symptom but, adds Dr. Schaffner, it may have to do with clotting in the smaller blood vessels. Read how a severe case of Covid-19 cost this man his toes and half of his leg.

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Covid toes seem to be just one of several skin symptoms linked with Covid-19, according to a March 2020 report in The Journal of the European Academy of Dermatology and Venereology (JEADV). The report from Italy found that 20 percent or 18 of 88 Covid-19 patients had skin-related symptoms. Some of these occurred at the beginning of the illness and others after hospitalization. Rash and hives were the most common, most appeared on the trunk of the body, and most cleared up in a few days. These symptoms didn’t seem to be linked with how severe the illness was. That report and another April 2020 letter in JEADV also described chicken-pox-like lesions in some patients. You may be interested in how to identify non-Covid-19 rash symptoms.

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One of the most concerning complications of Covid-19 infection has been strokes, often in very young patients. An April 2020 report in the New England Journal of Medicine (NEJM) reported five cases of stroke patients all under the age of 50 in New York City over a two-week period. This was a seven times greater increase over other two-week periods. These Covid-19-related strokes also seem to be occurring in sicker individuals, according to a March 2020 study in The Lancet.

Strokes associated with Covid-19 were also reported in Wuhan, China, in an April 2020 study in Thrombosis Research, where the novel coronavirus apparently began, and back during the 2004 SARS outbreak, according to a 2004 report in the Journal of Neurology. It can also happen after bouts of influenza, adds Dr. Schaffner. “You get an inflammation of the interior of the blood vessel and there is a tendency to get clotting,” explains Dr. Schaffner. “Part of this is an overresponse to this virus and this is all part of the collateral damage.”

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Heart problems

Heart damage in Covid-19 patients has also been noted, with some people even dying of cardiac arrest, according to Kaiser Health News. Several heart attacks have been associated with Covid-19, reveals an April 2020 letter in the NEJM. This may be because the virus can actually infect heart muscle, but it’s also possible that the heart problems are a result of the body’s response to the invader, with clotting playing a role. “An increased likelihood of clotting can have an effect on the heart as well,” adds Dr. Heinz. “It’s a similar concept of lack of blood flow to the heart muscle itself.”

People who have preexisting heart disease, including hypertension, are already at a higher risk of complications from Covid-19.

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Altered mental state

Although the data is still preliminary, experts have observed altered mental states or confusion in some patients with Covid-19, according to April 2020 studies published in JAMA Neurology and the NEJM. Again, it’s not always clear if the virus is responsible for the changes, especially when the symptoms appear in someone who is older. “Just having a 75-year-old patient with fever can make them a little goofy,” says Dr. Heinz, who also headed the Obama Administration’s domestic response to the Ebola crisis. “That complicates our ability to say it’s related to this virus. It could be something specific, but [it] also could be a very sick person in an unfamiliar place with other conditions.” Like every other aspect of Covid-19, Dr. Heinz adds, this “needs to be better defined and studied.”

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Diarrhea, nausea, vomiting, and reduced appetite

Gastrointestinal (GI) symptoms are turning out to be more common in coronavirus patients than once thought, even raising the possibility that the virus can be transmitted through feces, suggests an April 2020 study published in Gastroenterology. “There is significant GI distress and diarrheal-type symptoms,” confirms Dr. Heinz.

Another investigation in Gastroenterology into 116 Covid-19 patients at Stanford University found that almost one-third had GI complaints, most of them mild. In a March 2020 study, published online in Alimentary Pharmacology & Therapeutics, researchers reported that the most common GI symptom in children and adults was diarrhea. Related symptoms included lack of appetite (present in one-third to almost one-half of patients, says Dr. Schaffner), nausea, vomiting, and abdominal pain. Sometimes, patients experienced GI symptoms even when there were no respiratory symptoms.

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Kidney injury

As many as 15 percent of Covid-19 patients may experience kidney injury, reveals an April 2020 study in the American Journal of Kidney Diseases. And coronavirus has been found in the kidneys, making the injuries likely “a combination of the virus itself being transported to those organs causing some invasion plus the inflammatory response that’s evoked when the virus is in those tissues,” Dr. Schaffner explains. As with strokes and cardiac problems, clotting may be involved. Tons of little capillaries perform the filtering functions of the kidney, getting rid of waste. “When you have a clotting cascade, they plug up and block off,” says Dr. Heinz. People with kidney disease are already at a higher risk of developing severe disease from the coronavirus. Here’s what you need to know about coronavirus testing.

close up of man's eye with conjuntivitis
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Eye inflammation

Healthcare professionals have noticed inflammation around the eyes of Covid patients, also called conjunctivitis, says Dr. Glatt, who is also chairman of medicine and hospital epidemiologist at Mount Sinai South Nassau and professor of medicine at the Icahn School of Medicine at Mount Sinai in New York City.

Again, the evidence is preliminary, but an April 2020 study in Acta Ophthamologica found that more than a quarter of 56 patients with Covid-19 had ocular symptoms, 11 percent of them appearing before other symptoms. And a study published last month in the Journal of Medical Virology found that 1.1 percent of patients with Covid-19, who were hospitalized, had conjunctivitis. The symptom is more than three times as common in patients with severe illness, meaning it could be a sign of more complications.

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Guillain-Barre Syndrome

Between February 28 and March 21 of this year, doctors at three hospitals in northern Italy noted five coronavirus patients who had Guillain-Barre syndrome. This rare disease is associated with different viral infections, and it prompts the immune system to attack healthy nerves. In the April 2020 NEJM report, the main symptoms in the Covid patients were weakness and a burning sensation in the legs, then some facial paralysis, which appeared five to 10 days after other symptoms. Meanwhile, the JAMA Neurology study of 214 patients in Wuhan mentioned earlier, found that 36.4 percent had neurological symptoms such as dizziness, seizures, and nerve pain. Most of the patients had severe disease.

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Toxic shock syndrome

There have been reports of children suffering systemic illnesses reminiscent of toxic shock syndrome and Kawasaki disease. Most had tested positive for the coronavirus but some had not. On May 4, the New York City Department of Health issued a bulletin that 15 children in that city had become acutely ill and been hospitalized with similar symptoms, including fever, and asked doctors to be on the alert for more cases. Toxic shock syndrome is caused by bacteria and one of the main symptoms is a sudden fever of 102 or higher, according to the American Academy of Family Physicians. Kawasaki disease is also marked by acute fever, says the CDC.

Learn about the best at-home thermometers to monitor for Covid-19.