One of the first confirmed cases in Bangor spoke to the Chronicle about life with the virus from his quarantine at home.
Anthony Barnes, 25, has been given Tamiflu after contracting swine flu whilst visiting Anglesey on Sunday.
He said: "I felt ok for most of the day before it hit me on Sunday night and I virtually passed out for about 14 hours.
"On Monday I had really bad sinus congestion which got worse and worse, and I've been coughing so much that there's small amounts of blood in
my phlegm. I'm usually pretty robust but this has knocked me for six."
Mr Barnes, a labourer by trade, added: "I called the doctor this morning (Wednesday) and spoke to a specialist who confirmed I had swine flu and was in the medium risk category.
"The general gist of the advice was to stay at home and take plenty of fluids, but I'm a bit disappointed that my surgery didn't have Tamiflu to give out straight away."
Concerned partner Lucy Northage, 20, who collected the Tamiflu from Ysbyty Gwynedd, said: "We live together and do everything together 24/7 so I am a bit worried about having swine flu, but far more so about him - he seems to be getting worse by the moment.
"You know that swine flu is out there but you never think it's going to affect someone you love."
Doctors at the regional health agencies have urged anyone exhibiting swine flu symptoms to stay at home, and not go to their GP, the out of hours service or the hospital accident and emergency, as they risk spreading the illness.
Dr Roland Salmon, director of the communicable disease surveillance centre, National Public Health Service for Wales, said: "We have learnt that, in the majority of cases it is mild although proving severe for a small minority.
"Most people recover from infection without the need for hospitalisation or medical care."
You can check your symptoms by calling the Swine Flu Information Line on 0800 1 513513, and if concerns persist, call NHS Direct Wales on 0845 4647.