People who experience chills, loss of appetite, headache or muscle aches could be infected with Covid-19, a major study said on Wednesday.
Imperial College London researchers examined test results and questionnaires submitted by more than one million people between June 2020 and January 2021.
They found people displaying these symptoms were more likely to test positive for coronavirus.
According to UK health guidance, people are encouraged to get a Covid-19 test only if they experience symptoms including fever, new persistent cough and loss of smell or taste.
The React study found that the more symptoms a person displayed, the more likely they were to test positive for coronavirus.
However, researchers noted that about 60 per cent of infected people did not report any symptoms in the week leading up to their test.
There was also a variation in symptoms depending on age, with headaches reported mostly among children between the ages of five and 17.
Appetite loss was reported in adults of all ages, while aching muscles were experienced by people aged 18 to 54.
Infected five to 17-year-olds were less likely to report fever, persistent cough and appetite loss compared with adults.
Researchers said that more Covid-19 infections could be detected if people experiencing the new symptoms were encouraged to come forward.
"These new findings suggest many people with Covid-19 won't be getting tested – and therefore won't be self-isolating – because their symptoms don't match those used in current public health guidance to help identify infected people," research director Prof Paul Elliott said.
"We understand that there is a need for clear testing criteria and that including lots of symptoms that are commonly found in other illnesses like seasonal flu could risk people self-isolating unnecessarily.
"I hope that our findings on the most informative symptoms mean that the testing programme can take advantage of the most up-to-date evidence, helping to identify more infected people.”
