Although many people are only now becoming aware of it, adenovirus is being widely described as a “mystery illness spreading worldwide,” and that description feels accurate when you consider how many people are reporting symptoms at the moment. Adenovirus can cause fever, a runny nose, sore throat, and stomach discomfort, which makes it difficult to distinguish from a regular cold or the so-called “super flu” that is currently circulating. If you are feeling unwell, or concerned about catching an infection just before the holiday season, Dr Deborah Lee from Dr Fox Online Pharmacy explains how to tell adenovirus apart from the common cold and from the H3N2 flu strain.What Is Adenovirus?Adenovirus refers to a large group of viruses that can lead to infections ranging from mild to more severe. These viruses can affect the respiratory tract, eyes, digestive system, and urinary tract, often causing symptoms that look very similar to a cold or flu. Adenoviruses are hardy, spread mainly through respiratory droplets, and can infect people throughout the year. Children and individuals with weaker immune systems may experience more serious illness, but most people recover with rest and fluids, according to the Cleveland Clinic.Adenovirus vs Cold: How Does Adenovirus Differ From Common Cold?Adenovirus is one of several viruses that can trigger cold-like symptoms. It helps to think of a cold as a set of symptoms rather than a single illness, with adenovirus being just one possible cause. “Adenovirus is just one virus that can cause the common cold,” says Dr Lee. She adds that many other viruses can also be responsible, including respiratory syncytial virus (RSV), rhinoviruses, parainfluenza viruses, and coronaviruses.Identifying the exact virus behind your cold symptoms is very difficult. “It is pretty much impossible for you or a doctor to know which virus is causing your cold symptoms,” Dr Lee explains.Adenovirus vs Flu: How Does Adenovirus Differ From The Flu?“The flu can be extremely unpleasant, whereas adenovirus is usually mild,” Dr Lee says when comparing the two. She explains that flu symptoms often appear suddenly, sometimes within hours, and are usually marked by a high fever and severe discomfort.According to Dr Lee, flu symptoms can include:A high temperature between 38°C and 40°CJoint pain and muscle achesHeadacheSore throatBlocked or stuffy noseDry coughExtreme fatigueIn contrast, adenovirus symptoms, when they appear at all, tend to develop slowly over several days, Dr Lee notes.Other important differences between adenovirus and flu include:Adenovirus infections can occur at any time of year, while flu is more common during winterAdenovirus frequently causes pink eye, whereas influenza may lead to red or irritated eyes but less commonlyAdenovirus often causes digestive symptoms such as vomiting and diarrhoea, while flu can cause these but does so less oftenAdenovirus is generally less likely to cause serious complications than influenzaAdenovirus: How To Tell If You Have Adenovirus Or Cold Or Flu?Although adenovirus and common cold symptoms often overlap, the intensity of “super flu” symptoms usually stands out. Even so, Dr Lee explains, “The only way to really know the cause of your symptoms is to have a swab taken by a medical practitioner. This may be from the nose, throat, eye, urine, or stool.”In most cases, testing is unnecessary and unlikely to be offered. “Because the vast majority of these viral infections are mild and self-limiting, this is rarely done,” says Dr Lee. “Treatment for any cold is symptomatic only.” She adds that extra caution is needed for babies and young children, older adults, pregnant women, and people with weakened immune systems.