Mikaela Shiffrin said she felt like she was coming down with something before her first run in the women's slalom.
Shiffrin is attempting to defend her gold medal from Sochi in the event. She was .48 seconds behind the leader while the first run was still underway.
NBC reported that Shiffrin was "vomiting heavily" just moments before her run. They mentioned her struggle with nerves in the past, but after her run, Shiffrin said it felt more like "a virus."
"It was kind of sudden, it kind of felt like a virus. Less about nerves," she told NBC's Heather Cox.
She said she would take one of her famous naps before her second run, but that she would not be holding back.
Shiffrin has battled with nerves and has been close to vomiting before races in the past.
However, the Norovirus has been reportedly going around in PyeongChang. Cases of the virus continue to rise. There are about 200 people who are infected, according to reports.
The Norovirus is highly contagious and includes symptoms of diarrhea, stomach pain, vomiting and nausea.
The infected have mostly been staff and security members. There is no known Olympic athlete with the virus.
