? Important News! CoughPro has moved to a subscription model. Learn more here

How to Tell If You Have COVID or Flu: Similarities and Differences

Dr. Michelle Frank


March 15, 2023
CoughPro is not a medical product. It is a wellness app intended only for users to obtain a better understanding of their cough. It is not intended to diagnose, monitor, or treat any illness.

We at Hyfe, Inc., are a company devoted to working on tools to better understand the importance of cough. It is Hyfe’s intention in the future to seek regulatory approval for medical products that analyze cough in order that they may be used to diagnose, monitor, and facilitate better treatment of respiratory illnesses.

a woman lying on bed is sneezing | COVID or Flu? How to Track Your Health This Flu Season | Feature

With the recent COVID-19 pandemic, we have a new viral “flu” making its rounds, especially during the changing seasons. With their overlapping symptoms, however, it can be relatively difficult to know whether you have COVID or flu. 

Evolving strains in both influenza and the COVID-19 virus have necessitated being up-to-date on vaccinations. But, as we saw during the pandemic, being vaccinated hasn’t limited the chances of getting infected. It reduces the intensity of symptoms. Having fewer symptoms can actually make your viral illness more of a puzzle when it comes to guessing which infection you may have.

Therefore, this article will explore the signs you can look out for to be able to differentiate between the flu and COVID-19.

Recognizing Flu Symptoms

When we generally refer to the “flu”, we are talking about the infection caused by the influenza virus. This is also known as seasonal flu as it is frequently observed during the winter months.

According to the World Health Organization, influenza often appears in epidemics in temperate regions during the winter months, while in tropical areas, it can have outbreaks throughout the year1.

Influenza can affect all age groups. But certain individuals are at a higher risk of severe infection when compared to the rest. Pregnant women, children, adults over the age of 65, those with chronic medical conditions such as kidney disease, asthma, diabetes, and cancer, and those who are immunocompromised are a few groups that fall on this list2.

For the most part, however, influenza shows up as a sudden onset of high fever accompanied by a dry cough, malaise (general feeling of being ill), severe body aches, a runny nose, and a sore throat. Flu symptoms might not be severe for those who have strong immune symptoms. A runny nose, mild fever, and body aches might be the only indication of the flu. These symptoms often subside on their own in a week or two. However, the severity of symptoms can be higher among those who have a weakened immune system.

Since, for most, the flu resolves on its own in a couple of weeks with over-the-counter medicines such as paracetamol or cough syrups, many do not get a test. The seasonal flu vaccine also helps to lower the severity of symptoms, reducing the likelihood of ever needing significant medical attention.

A sick woman blowing her nose

Recognizing COVID-19 Symptoms

Some of the initial signs that indicate an underlying COVID-19 infection include a high fever, sore throat, and a dry persistent cough. During the pandemic, a vast majority of individuals had negligible symptoms even during their infective stages. Many were asymptomatic carriers, which was a reason for the easy spread of the virus among communities.

A tell-tale symptom of COVID-19 during the pandemic was a loss or change in smell and taste. But, while a frequently associated symptom of COVID-19, there has been a high variability, between 5–98%, of people who reported an alteration in their smell3.

Among other symptoms, headache, nausea, diarrhea, a sore throat, and shortness of breath have also been recorded as symptoms of COVID.

Similar to influenza, individuals who fell in a high-risk category often presented with more severe symptoms of COVID-19. Patients among whom the most serious respiratory consequences were observed were those with diabetes, kidney disease, lung conditions such as COPD, or who were immunocompromised. Their oxygen saturation was frequently low during their COVID-19 infection and was a parameter to document the respiratory progression of viral infection4.

Differentiating COVID-19 vs the Flu

Both viral infections appear to have similar presentations, especially during the initial phases of illness. High fever, sore throat, body aches, and cough are among the first signs of infection for both. 

However, there are distinct clues that can suggest whether you have COVID or the flu5.

Both COVID-19 and the flu are spread through respiratory droplets while sneezing, coughing, or even talking. The infectious phase of influenza is usually the first 3–4 days of symptom presentation. This contrasts with COVID-19, where the day just before symptoms begin is the infectious peak.

Influenza infections have a shorter incubation period than COVID-196. Symptoms usually show up a few days following exposure, whereas with COVID-19 it can take up to two weeks before the fever, loss of smell, and respiratory signs are present. 

A table with an overview of similarities and differences between COVID-19 and the flu

Coughs with both viral infections are frequently dry and persistent. However, with COVID-19 cough intensity could be worse in patients with severe respiratory involvement, often leaving them gasping for breath. Cough was also a sign of long COVID-19, along with dyspnea, pain, and brain fog7.

Loss of smell and taste was characteristically associated with COVID-19 but not the flu. While symptoms like exhaustion, headaches, and body aches are present with both, but appear to be more severe with the flu.

Studies have also indicated that blood work can also differ between patients with COVID-19 and influenza infections. Liver injury, shown by raised liver enzymes and significant decreases in platelets, was likely to be seen among patients with COVID-19 but not the flu8.

For both flu and COVID-19, gastrointestinal (GI) symptoms such as diarrhea and vomiting were more prominent among children. With COVID-19 specifically, there has also been documentation of multi-system inflammatory syndrome, where GI symptoms predominate along with a rash, conjunctivitis, and other signs of circulating inflammation9.


With life moving back to its normalcy after the COVID-19 pandemic, we expect a new flu virus to circulate during the seasonal outbreaks. With changes in season and fluctuating immunity, co-infection with both influenza and COVID-19 is also possible, especially among those with compromised immune systems10.

Vaccines are available for both COVID-19 and the flu. Following immunization schedules can reduce the intensity of infection and also reduce spread. Identifying signs early can also prompt early treatment and the use of preventive measures to reduce the spread of both the flu and COVID-19.

Both COVID-19 and the flu spread easily. This means observing hints of either viral illness should prompt a doctor’s visit, especially to prevent severe disease severity.

  1. WHO. (2023, January 12). Influenza (Seasonal). Retrieved March 11 2023https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal)[]
  2. Uyeki T. M. (2020). High-risk Groups for Influenza Complications. JAMA, 324(22), 2334. https://doi.org/10.1001/jama.2020.21869[]
  3. Mullol, J., Alobid, I., Mariño-Sánchez, F., Izquierdo-Domínguez, A., Marin, C., Klimek, L., Wang, D. Y., & Liu, Z. (2020). The Loss of Smell and Taste in the COVID-19 Outbreak: a Tale of Many Countries. Current allergy and asthma reports, 20(10), 61. https://doi.org/10.1007/s11882-020-00961-1[]
  4. Rodriguez C. (2020). Using pulse oximetry to monitor high-risk patients with COVID-19 at home. Nursing, 50(11), 15–16. https://doi.org/10.1097/01.NURSE.0000718376.94916.eb[]
  5. Li, Y., He, H., Gao, Y., Ou, Z., He, W., Chen, C., Fu, J., Xiong, H., & Chen, Q. (2021). Comparison of Clinical Characteristics for Distinguishing COVID-19 From Influenza During the Early Stages in Guangdong, China. Frontiers in medicine, 8, 733999. https://doi.org/10.3389/fmed.2021.733999[]
  6. Zayet, S., Kadiane-Oussou, N. J., Lepiller, Q., Zahra, H., Royer, P. Y., Toko, L., Gendrin, V., & Klopfenstein, T. (2020). Clinical features of COVID-19 and influenza: a comparative study on Nord Franche-Comte cluster. Microbes and infection, 22(9), 481–488. https://doi.org/10.1016/j.micinf.2020.05.016[]
  7. Song, W. J., Hui, C. K. M., Hull, J. H., Birring, S. S., McGarvey, L., Mazzone, S. B., & Chung, K. F. (2021). Confronting COVID-19-associated cough and the post-COVID syndrome: role of viral neurotropism, neuroinflammation, and neuroimmune responses. The Lancet. Respiratory medicine, 9(5), 533–544. https://doi.org/10.1016/S2213-2600(21)00125-9[]
  8. Chen, J., Pan, Y., Li, G., Xu, W., Zhang, L., Yuan, S., Xia, Y., Lu, P., & Zhang, J. (2021). Distinguishing between COVID-19 and influenza during the early stages by measurement of peripheral blood parameters. Journal of medical virology, 93(2), 1029–1037. https://doi.org/10.1002/jmv.26384[]
  9. Calitri, C., Fumi, I., Ignaccolo, M. G., Banino, E., Benetti, S., Lupica, M. M., Fantone, F., Pace, M., & Garofalo, F. (2021). Gastrointestinal involvement in paediatric COVID-19 - from pathogenesis to clinical management: A comprehensive review. World journal of gastroenterology, 27(23), 3303–3316. https://doi.org/10.3748/wjg.v27.i23.3303[]
  10. Dadashi, M., Khaleghnejad, S., Abedi Elkhichi, P., Goudarzi, M., Goudarzi, H., Taghavi, A., Vaezjalali, M., & Hajikhani, B. (2021). COVID-19 and Influenza Co-infection: A Systematic Review and Meta-Analysis. Frontiers in medicine, 8, 681469. https://doi.org/10.3389/fmed.2021.681469[]

Your Cough Matters

Based on our results in Google Play & App Store
  • Excellent, insightful
    By dust mite dan - Apr 7, 2023 - App Store
    This app is easy to use, aesthetically pleasing and has provided me with useful information about my cough and disease patterns that have improved my overall health!

    Try CoughPro for Free
  • Great app!
    by Imtfx0019 — Dec 6, 2022 - App Store
    Impressed with how well it detected my coughs, even very slight ones.
    Try CoughPro for Free
  • App is Great!
    by HBert Quach — Jan 22, 2023, - Google Play
    App is great at tracking cough when little ones are sick. I treat it as a early warning indicator before the cold gets back. Customer service is awesome, they actually respond to all my questions.
    Try CoughPro for Free
  • Great Experience
    by Christi Hammock — Mar 7, 2023, - Google Play

    I had an issue logging into the new app but I contacted the support team and they were awesome in helping me figure out the issue. It turned out to be a technical issue which they resolved very quickly and I was kept in the loop on the status from start to finish. This app is really helpful when talking to my doctor too..
    Try CoughPro for Free
  • Impressive app
    By KayakTina - Apr 7, 2023 - App Store
    "The app accurately is recording my coughs with excellent ways to review the results. I can add notes to help me identify patterns or have accurate information for my physicians. I’ve hoped for an app like this for years to help me accurately track the amount of coughing I’m doing"
    Try CoughPro for Free
  • Accurate count of coughs
    by Beardonna — Mar 8, 2023 - App Store

    Just installed the app. Very accurate measuring coughs so far! Cannot wait to see how much coughing I do while sleeping. I'll have a better picture to discuss with my physician at my next visit.

    Try CoughPro for Free

Recent Posts

© 2024 All Rights Reserved.
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram