(Image Credit: Andy Barr/Carmona for Arizona)

The Hippocratic Oath has triumphed over politics in Arizona.

Democratic Senate candidate and former U.S. Surgeon General Richard Carmona evidently still believes in it. Carmona performed an impromptu medical exam Wednesday on a campaign tracker, who has been following Carmona at public events with a camera, in the apparent hopes of catching the candidate doing or saying something that could be used against him.

After Carmona, 62, had finished walking in a Fourth of July parade in Flagstaff, the tracker's camera battery ran out, Carmona spokesman Andy Barr said.

"He was complaining about a bump on his leg," Barr said in an email.

Carmona "offered to check it out. He said the kid probably has a hematoma and likely needs to have it drained. He suggested the tracker have his own doctor check it out to confirm first."

Barr tweeted the photo Wednesday.

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Carmona served as U.S. Surgeon General under President George W. Bush. After serving in Vietnam, Carmona practiced as a surgeon in Arizona while also serving as a SWAT team leader for the Pima County, Ariz., sheriff's department.

It's unclear for whom the tracker works, and he has declined to tell Carmona's campaign staff, Barr said. He does not work for Carmona's chief rival, Rep. Jeff Flake, who is favored to win the Republican Senate nomination in August, a Flake spokesman said.

The Arizona Republican Party would not confirm to ABC News whether it employs a tracker following Carmona.

"He's been following us for a bit," Barr said. "He had been doing his job the full time and is pretty persistent."