"I had never had one before, 26 years I've been living," Porter told The Denver Post on Thursday. "Before the San Diego game, I don't know if it was the medication I was taking or it was a setback, but they decided to hold me back."
Porter returned to practice this week, but he still hasn't been cleared to play. He was limited Wednesday and missed Thursday's practice because of a doctor's appointment.
"Right now, Tracy is being evaluated," Broncos coach John Fox said. "When he's cleared to physically be able to practice, he'll be out there. I don't know all the symptoms. When we figure out how to deal with the illness, then he'll be out here."
Porter also tweeted: "I would like to thank EVERYONE for the prayers and wishes. It really means a lot to me."@kareemcopeland.