Flu vs. Flu-Like Illness: What You Need To Know

The flu season is currently gripping the U.S. with estimates by CDC revealing  9.7 million citizens were diagnosed with the flu as of January 4. In total, about 87,000 hospitalizations and 4,800 deaths were reported.

Not just influenza A and B viruses, a confusing but similar diagnosis called the influenza-like illness (ILI) reported by several outpatient facilities was on the rise, but decreased recently since enough people have sought help. 

This year, the flu season has taken a unique turn since the numbers of influenza B virus having affected adults are record breaking when considering statistics of the past 27 years. However, influenza-like-illnesses accompany a cold and a sore throat with fever at a minimum temperature of 100°

F.  Importantly, no deaths have occured due to ILIs. 


“Flu-like illness can include other respiratory viruses that could make people feel that way -- common cold viruses, RSV, parainfluenza, rhinovirus -- the most common cause of the common cold. All can cause symptoms similar to the flu,” Angela Campbell, medical officer in the CDC’s Flu Division in Atlanta, told WebMD.

While the flu can be tested by swiping a swab on a person’s nose or throat, the flu-like illness cannot be tested with medical equipment. Doctors just go by taking all the symptoms into account. Clinicians also find it hard to differentiate between colds and respiratory problems from the flu, hence they just treat the symptoms to be careful


Doctors don’t perform a flu test because the treatment will be restricted to addressing the symptoms. Since the tests are not cheap and not completely accurate, doctors often do not see the point of the flu test when identifying similar symptoms. They are also more sure of the symptoms of flu during the outbreak season.  

“For the most part, the official flu tests are done if you are hospitalized with an influenza-like illness. Some doctors will have the rapid test available in their offices, but the rapid test can be very inaccurate,”  William Schaffner, infectious disease specialist at Vanderbilt University School of Medicine, explained to WebMD.  

“So a lot of people say if you are in the middle of an influenza outbreak and a patient comes into the office with an illness that looks like influenza, just go ahead and treat them. Don’t bother with the test.”


Antiviral drugs treat both flu-like symptoms as well as confirmed cases of the flu. For best results, they should be taken within 48 hours of the symptoms appearing, although antiviral medication can also negate some of the effects of severe flu complications. 

In 2018, baloxavir marboxil (Xofluza) was approved by the FDA to treat early stages of the influenza. The other drugs approved by the FDA are Oseltamivir (Tamiflu), Peramivir (Rapivab) and Zanamivir (Relenza).

Flu Season As of January 4, about 87,000 hospitalizations and 4,800 deaths related to the flu were reported to the CDC. Raj Eiamworakul/Unsplash

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