The official list of coronavirus symptoms should be expanded as the current one could be leading to missed cases, experts have said.
A high temperature, new or continuous cough, and a loss or change in smell or taste are the only three "main symptoms" of COVID-19, according to the NHS.
But a group of experts says that the UK should follow the World Health Organization (WHO) and other countries in updating that list as several others are now regularly reported - particularly with the emergence of the Delta (Indian) variant.
The US Centers for Disease Control lists 14 official symptoms, while the WHO counts 12.
According to the latest data from the Office for National Statistics (ONS) 42% of symptomatic people had a cough, 39% suffered a headache and 38% experienced fatigue.
A quarter of people reported muscle aches and 32% said they had a sore throat.
By comparison, 33% had a fever, only 21% lost their sense of smell and 15% their sense of taste.
Writing in the British Medical Journal, Dr Alex Crozier - a biosciences expert - and Professor Calum Semple - an outbreak medicine doctor on the government's advisory SAGE committee - say the small list of official symptoms is having various negative effects.
They argue that it "hampers efforts to interrupt transmission" of the virus, because cases with non-traditional symptoms are being missed.
The experts also say many people are unable to access the more accurate PCR tests because they show irregular symptoms. This results in fewer cases being detected early - when people are most contagious.
They add that non-traditional symptoms "often manifest earlier".
The group of scientists do note however that people are already "bypassing" the rules on having listed symptoms to qualify for PCR testing.
They also suggest an increased demand for lab-tested swabs could "overwhelm" capacity.
"The UK's decision to adopt a narrow case definition was based on ease of communication, avoiding confusion with other infections and preserving testing capacity," they wrote.
"This situation is now different. COVID-19 is associated with a wide range of symptoms.
"Many patients do not experience the UK's official case-defining symptoms, initially, or ever, and other symptoms often manifest earlier.
"Limiting the symptomatic testing to those with these official symptoms will miss or delay identification of many COVID cases.
"Expanding the clinical case definition of COVID-19, the criteria for self-isolation, and eligibility for symptomatic testing could improve the UK's pandemic response."
The Department of Health and Social Care said it "acknowledges" that COVID is associated with "a much longer list of symptoms" and official guidelines are "kept under review".
They said that only people with the three key symptoms should have a PCR test, as rapid lateral flow ones are available for the asymptomatic or people with non-traditional symptoms.