Omicron, cold, or flu? Here's why symptoms may not always make all the difference

Omicron – the new, highly transmissible variant of the SARS-CoV-2 coronavirus – has taken the world by storm, driving up daily Covid-19 numbers in exceptional measures. Although there currently is a debate among public health professionals and infectious diseases experts on how "mild" the Omicron variant really is on humans, a number of studies have suggested that its feeble attack on the lungs could make it less dangerous than the other, more fatal variants which came prior, such as Delta.

However, almost all scientists and medical professionals advise caution, given the highly mutated form of the virus and the unusually tall number of evolutions that the variant has been capable of. Amid such a scenario, it is sometimes challenging for the average citizen – when faced with symptoms also resembling that of common cold or influenza – to be sure of whether they are infected with Omicron.

In all three cases of common cold, influenza, or a coronavirus disease (Covid-19) infection caused by Omicron, the symptoms include a sore throat, runny nose, body ache, and fever. The prime suspect, in almost all of these cases, is the common cold. It might also be tempting to consider influenza, which tends to peak in the middle of winter from early October to mid-February.

However, given that Omicron cases have skyrocketed globally over the past few days, it is also highly likely that the person might have contracted the fast-spreading variant.

According to experts, however, there is no quick and surefire way to know if one has Omicron. Although there are a few workarounds to land an educated guess, the importance of testing is revealed here more than ever since it is difficult to tell Omicron from the common cold, in particular, based on symptoms alone.

Professor Eskild Petersen, of the Aarhus University Hospital in Denmark, was quoted as saying by a media publication, "A common cold and Omicron is, in my view, impossible to distinguish."

The point was also echoed by Dr Andrew Freedman, an infectious diseases specialist at Cardiff University in the UK. "A lot of people, particularly vaccinated people, are getting what would otherwise be thought of as the common cold."

Here are a few general symptoms of Covid-19, influenza, and the common cold, arranged according to their frequency:

Dry cough: Covid-19 (frequent), flu (frequent), cold (occasionally)

Fever: Covid-19 (frequent), flu (frequent), cold (rare)

Stuffy nose: Covid-19 (rare), flu (sometimes), cold (frequent)

Sore throat: Covid-19 (sometimes), flu (sometimes), cold (frequent)

Shortness of breath: Covid-19 (sometimes), flu (not observed), cold (not observed)

Headache: Covid-19 (sometimes), flu (frequent), cold (not observed)

Body aches: Covid-19 (sometimes), flu (frequent), cold (frequent)

Sneezing: Covid-19 (not observed), flu (not observed), cold (frequent)

Exhaustion: Covid-19 (sometimes), flu (frequent), cold (sometimes)

Diarrhoea: Covid-19 (rare), flu (sometimes), cold (not observed)

Even so, the best advice given by professionals, as always, is to get tested and self-isolate at home in case symptoms appear. While the sensitivity of rapid tests in detecting Omicron might be a bit lower as of now, RT-PCR (reverse transcription-polymerase chain reaction) tests are generally considered to be the most steadfast and accurate way of detecting a potential Covid-19 infection. In case Covid-19 is detected, the patient's sample will be sent to an appropriate laboratory to detect the variant of the coronavirus.

Jill Weatherhead, an infectious disease expert at the Baylor College of Medicine in Houston, told the National Geographic magazine that "the best thing we can do is identify what our risk tolerances are and make sure that we're protecting others", especially during this highly contagious period of time.