Dr David Hepburn, who works at the Royal Gwent Hospital in Newport, said he believes he caught the virus through colleagues at work, or possibly "someone out in the street".
He said he is witnessing his team looking after "a lot of patients" who are unwell with coronavirus.
"Some of them are younger than I am - and they are certainly not the frail elderly people that may be some of us have been led to believe we would be seeing.
"They are young, they are fit and they have young families, as do I."
He described some of the symptoms he experienced which "started off very innocuously".
"I'm on the mend now, thankfully - I hope", David added.
He said, "I can't emphasise enough how sick this can make you", as he urged people to listen to the current advice, which involves strict new anti-virus measures, including a ban on gatherings of more than two and orders for people to stay at home.
"Please please listen to the advice. This is a small sacrifice for a short period of time - and then life will go back to normal again. But we have to protect everybody, and we have to protect the NHS."
Coronavirus: Everything you need to know