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BA.5 Symptoms Usually Appear in This Order

Study finds what the most common COVID symptoms are and the order they often appear in. 
FACT CHECKED BY Emilia Paluszek

Research from the University of Southern California is shedding light on COVID symptoms and the order in which they usually appear. The 2020 study was published in the journal Frontiers in Public Health and led by doctoral candidate Joseph Larsen and his colleagues with faculty advisers Peter Kuhn and James Hicks at the USC Michelson Center for Convergent Bioscience's Convergent Science Institute in Cancer finds that there are four to five COVID common symptoms that happen in a sequences and explains why this information is so significant. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


Data Collection


The study states, "The main dataset of COVID-19 patients of the World Health Organization, containing 55,924 confirmed cases, was obtained through review of national and local governmental reports and observations made during visits to areas with infected individuals in China that occurred from February 16 to 24, 2020. A confirmation dataset of COVID-19 patients, containing 1,099 confirmed cases, was obtained by the China Medical Treatment Expert Group for COVID-19 from medical records and other compiled data of hospitalized patients and outpatients that were diagnosed with COVID-19. This data was reported to the National Health Commission of China from December 11, 2019 to January 29, 2020."


Why the Order of COVID Symptoms is Important

Sick woman lying in bed with high fever.

USC News reports, "This order is especially important to know when we have overlapping cycles of illnesses like the flu that coincide with infections of COVID-19," said Kuhn, professor of medicine, biomedical engineering, and aerospace and mechanical engineering at the USC Dornsife College of Letters, Arts and Sciences. "Doctors can determine what steps to take to care for the patient, and they may prevent the patient's condition from worsening."


The Order of Symptoms

Sick woman on couch

The study finds, "A person infected with COVID-19 is most likely to experience symptoms in the order of fever, cough, nausea/vomiting, then diarrhea. The least likely path starts at diarrhea and nausea/vomiting and is followed by cough, and finally fever."


Decrease in Hospitalization Rates Could Happen by Knowing the COVID Symptom Order

Young sick woman lies tired in bed with a face mask and holds her head because of a headache.

"Given that there are now better approaches to treatments for COVID-19, identifying patients earlier could reduce hospitalization time," said Larsen, the study's lead author and a USC Dornsife professor. He also stated, "The order of the symptoms matter. Knowing that each illness progresses differently means that doctors can identify sooner whether someone likely has COVID-19, or another illness, which can help them make better treatment decisions." 


The Key Difference in COVID VS Other Viruses

Young woman sitting alone on her sofa at home and coughing.

COVID was compared to other SARS and MERS and researchers found one major difference with symptoms. "We found evidence that supports the notion that there is a most common order of discernible symptoms in COVID-19 that is also different from other prominent respiratory diseases," according to the study. "The most likely initial symptom is fever in the three diseases studied that are caused by coronaviruses (i.e., COVID-19, SARS, and MERS) and cough in influenza. The most likely order of the four easily discernible symptoms is identical in MERS and SARS, but the most likely path of COVID-19 has one key difference. The first two symptoms of COVID-19, SARS, and MERS are fever and cough. However, the upper GI tract (i.e., nausea/vomiting) seems to be affected before the lower GI tract (i.e., diarrhea) in COVID-19, which is the opposite from MERS and SARS. 

In all diseases, we found that fever and cough occur before nausea/vomiting and diarrhea. When observing the set of seven symptoms including three subjective ones (i.e., sore throat, headache, and myalgia), we found that the initial symptoms of the most likely path are the same as in the most likely path of the four discernible symptoms. Also, in both the four and seven symptoms implementations, the GI tract symptoms are last. A separate MERS dataset included the initial symptoms of patients on admission, which listed the symptoms from highest to lowest probability as fever, myalgia, cough, and diarrhea. This order is similar to the most likely path that we determined." And don't visit any of these 35 Places You're Most Likely to Catch COVID.

Heather Newgen
Heather Newgen has two decades of experience reporting and writing about health, fitness, entertainment and travel. Heather currently freelances for several publications. Read more about Heather