Vickers was hospitalized two nights last week after feeling chest pains during a visit to Washington, D.C. Testing revealed the clots, and Vickers missed last weekend's race at Dover.
Vickers returned to North Carolina following his release from the hospital Friday night, but said a recurrence of chest pains sent him back to the hospital the next day. He spent another two nights hospitalized, and the decision to sit out the remainder of the season to receive treatment was made shortly after.
"This is what I love to do, this is my life," Vickers said Friday at Charlotte Motor Speedway, where he made his first public appearance since his ordeal began last Wednesday. "This is what I love to do, and I fully intend on doing it again."
The 26-year-old Vickers is being treated for a pulmonary embolism with the blood thinner Coumadin, and his physician couldn't clear him to race because of the dangers of the driver being injured in a crash.
"It is not advisable for him to race while he's on blood thinners," said Dr. Steven Limentani of Carolina Hematology Oncology.
Vickers, seated between Limentani and Red Bull Racing general manager Jay Frye, then quickly lightened the mood.
"I can actually race on blood thinners, I just can't crash," he smiled. "So I told them if I promise I won't crash, will they let me race?
"The answer was 'No.' In my situation, let's just say the minimum was three months and the recommended is six months — for me to come back with eight races left in the year and to run the risk of having this happen again just to cut it short at three months, I don't think the reward really outweighs the risk. We're going to go the full stay here and be committed to resolving the issue for the rest of my life."
Limentani, who treated NASCAR team owner Rick Hendrick when he battled leukemia, said the clots in Vickers' lungs were "relatively small," but gave the driver pains similar to being punched in the ribs every time he took a breath.
The doctor said tests to determine what caused the clots will take a "number of weeks" to come back, and its possible they may never know.
"Sometimes the absence of data is the conclusion," Limentani said.
Limentani also shrugged off an Australian study that suggested drinking the energy drink Red Bull — the company both owns and sponsors Vickers' team — could contribute to blood clots. Limentani said the report was not conclusive and did not pertain to Vickers' situation.
Vickers bristled at the suggestion that drinking Red Bull might have caused it.
"I drink water, too, so if we're going to speculate, that could be it, too," Vickers said.
Vickers is in his seventh full season in the Sprint Cup Series and coming off his first appearance in the Chase for the championship. He was replaced in the No. 83 Toyota last weekend by Casey Mears, who will also drive the car in Saturday night's All-Star Race.
Frye said the team was still deciding how it will proceed the rest of the season, but indicated Mears could stay in the seat with possible consideration to using a road course specialist at those two races.
Vickers vowed to return in 2011.
"I do expect to be back in the car next season, and to win the Daytona 500," he said. "I'm dealing with two emotions: I want nothing more than to be back in the race car. At the same time, it's not my personality to focus on the negative. It's not who I am. It's not who I've always been. I'm going to make the most out of this.
"This is the cards I've been dealt and I can't change that right now. I'm going to do everything I can to be positive through this."