COVID vs flu vs viral fever: How to spot the difference and new symptoms to watch for

Published 14 July 2026 · local

With changing weather and an increase in seasonal infections, clinics are once again seeing people with fever, sore throat, cough and body aches. For most

With changing weather and an increase in seasonal infections, clinics are once again seeing people with fever, sore throat, cough and body aches. For most people, the biggest question is simple: Is it COVID-19, the flu, or just a viral fever? The challenge is that these illnesses often begin with similar symptoms, making it difficult to know exactly what is causing the infection during the first few days. While many viral illnesses can be managed with rest and fluids, COVID-19 and influenza can sometimes lead to complications, particularly in older adults, pregnant women, young children and people with chronic illnesses. Read Full Story Doctors say that although these infections overlap in many ways, there are important differences in how quickly symptoms appear, how severe they become and how long recovery takes. Paying attention to these clues and seeking medical advice when needed can help people receive the right treatment while reducing the risk of spreading infection to others. According to Dr Shridhar Deshmukh, MD General Medicine, Consultant Physician and Intensivist at Ruby Hall Clinic, Pune, COVID-19 today does not always look the way it did during the early days of the pandemic. While severe disease is less common in many people, the virus continues to evolve, and its symptoms can still differ from influenza and other viral infections. COVID-19: SYMPTOMS HAVE CHANGED, BUT IT CAN STILL CAUSE PROLONGED ILLNESS One of the biggest changes doctors have noticed is that COVID-19 often starts with symptoms affecting the upper respiratory tract. People with COVID-19 may experience Persistent sore throat Dry or lingering cough Stuffy or blocked nose Headache Fever Body aches Extreme tiredness Loss of appetite Nausea or diarrhoea in some cases Unlike influenza, COVID-19 symptoms often develop gradually over a day or two instead of appearing suddenly.

Another feature that still sets COVID-19 apart is fatigue. Even after the fever and cough improve, many patients continue to feel exhausted for days or even weeks. "COVID-19 is not just another viral infection. While many people recover without complications, it can leave patients feeling weak for a prolonged period," says Dr Deshmukh. INFLUENZA: A SUDDEN ILLNESS THAT HITS HARD Influenza, commonly known as the flu, usually announces itself much more dramatically. A person may feel perfectly healthy in the morning and develop high fever, chills and severe body aches by the afternoon. Common flu symptoms include Sudden high fever Chills Severe muscle pain Headache Dry cough Sore throat Runny nose Extreme weakness Doctors say the speed of onset is one of the easiest ways to distinguish influenza from COVID-19. Although the flu can make people feel extremely ill, most healthy adults begin recovering within five to seven days. WHAT ABOUT OTHER VIRAL FEVERS? Many common viruses, including adenovirus, enterovirus and parainfluenza viruses, can also cause fever and respiratory symptoms. Typical symptoms include Mild to moderate fever Sore throat Runny nose Mild cough Body aches Occasional stomach upset Compared with influenza, these illnesses are generally milder and improve within three to five days with supportive care such as Adequate rest Drinking plenty of fluids Fever-reducing medicines as advised by a doctor Nutritious meals Unlike COVID-19, these infections usually do not leave people with prolonged fatigue. COVID VS FLU VS VIRAL FEVER: KEY DIFFERENCES Feature COVID-19 Influenza (Flu) Common Viral Fever How symptoms begin Gradual Sudden Usually gradual Fever Common High and sudden Mild to moderate Sore throat Very common Common Common Cough Persistent Common Usually mild Body aches Common Severe Mild to moderate Fatigue Can last for weeks Severe but shorter Usually mild Stomach symptoms Sometimes Less common Can occur Recovery time 1–2 weeks or longer 5–7 days 3–5 days CAN YOU HAVE MORE THAN ONE INFECTION?