With winter illnesses circulating, a GP has explained how to tell whether you have a cold, Covid or flu. According to the UK Health Security Agency, the number of people being hospitalised with Covid has increased by 50 per cent in a week.
GP Dr Saira Bano, founder of SwiftDoctor, says the common ways people determine which virus they have are not reliable. She said: “People still tend to think flu will always knock you off your feet overnight or that Covid must cause a loss of taste or smell, but neither is a reliable rule. There are clues that can point you more towards one infection than another, including how quickly you become unwell, how exhausted or achy you feel, and which symptoms are most noticeable, but there’s a lot of overlap.
“The important thing is to look at the whole picture, consider testing where it could be useful, and know the warning signs that mean it’s time to get medical help rather than assuming it’s ‘just a cold’.”
Key differences between the viruses
Dr Bano added: “A cold tends to be more focused around the nose and throat, with a blocked or runny nose, sneezing, sore throat, hoarse voice and cough. It usually builds gradually over two or three days, and although you might feel rough, you can often still manage at least some of your normal activities.
“Flu is more likely to make you feel significantly unwell across your whole body, with fever, chills, muscle aches, headache, exhaustion and a cough, and it often comes on much more suddenly. You can still get a sore throat or runny nose with flu, so nasal symptoms don’t automatically mean it’s a cold.”
“Covid is particularly difficult to pick out because it can look like either. A sore throat, blocked or runny nose, cough, fever or chills, tiredness, headache and body aches can all occur, while some people may also experience shortness of breath, loss of appetite, nausea, diarrhoea or changes to their sense of taste or smell. Generally, suddenly developing a fever with significant muscle aches and exhaustion is more likely to point towards flu, while symptoms that gradually build around the nose and throat are more typical of a cold. Covid, however, can produce either pattern, which is why symptoms alone can’t give you a definite answer.”
Symptoms changed with new variants
Dr Bano said new Covid variants mean the symptoms have changed. She said: “A loss or change in your sense of taste or smell is still a recognised Covid symptom, but it isn’t the giveaway sign people may remember from earlier in the pandemic. It became much less common with Omicron compared with earlier variants, and an ordinary cold can also reduce your sense of smell, particularly if your nose is badly congested.
“So a change in taste or smell shouldn’t automatically be taken to mean you have Covid. Nausea, vomiting and diarrhoea can also occur with Covid and other respiratory viral infections, but they aren’t the dominant symptoms you’d normally expect with a straightforward cold. If vomiting and diarrhoea are the main problem, I’d also consider a stomach infection such as norovirus rather than immediately assuming it’s flu or Covid.”
Testing and vaccination advice
For most otherwise healthy people in England, routine Covid testing is no longer recommended simply because you have respiratory symptoms. There’s an important exception for people who are at higher risk of becoming seriously unwell and are eligible for Covid treatments. If that applies to you, it’s important to test promptly when symptoms develop because a positive result can affect access to treatment.
Whatever the infection, how unwell you feel still matters. If you have a temperature or don’t feel well enough to carry out your normal activities, you should try to stay at home and avoid close contact with other people, particularly anyone who’s more vulnerable to becoming seriously ill.
The NHS says anyone under 18 who tests positive should stay home for three days. Those over 18 should stay home for five days. And you should stay away from anyone vulnerable for 10 days.
For flu and Covid, most eligible adults in England can now receive their NHS vaccination. The autumn Covid vaccination programme is more targeted this year. In England, it includes adults aged 75 and over, residents of care homes for older adults and people aged six months and over who are immunosuppressed.
