A persistent cough is one of the tell tale signs of coronavirus infection.
THe NHS says anybody who develops a 'new, continuous cough' should stay at home and contact its Coronavirus Service to find out what to do next, as developing a persistent cough is a sign that they could have contracted Covid-19.
But what exactly is a persistent cough?
Dr Hilary Jones explained to viewers on Good Morning Britain.
He said: "What I mean by a persistent cough, is a cough that would be five or six times an hour, for at least half a day and more than that, probably two days.
"It's a new cough, a dry cough, it's not a productive cough with phlegm.
"It's come out of the blue, it's persistent, you're coughing a lot every hour, for at least half a day, but probably longer than that."
If a cough is new, frequent, with several bouts every hour, lasts more than half a day and does not produce any phlegm, then stay isolated - no trips to the shops or outside exercise - and contact the NHS.
The health service asks those with symptoms to contact its online coronavirus service, if they have internet access. Those who can't get online can call the NHS on 111.
The NHS' advice adds: "To protect others, do not go to places like a GP surgery, pharmacy or hospital. Stay at home."
