The candidate’s self-deprecating humor plays well on the trail. But McCain, who turns 72 on Aug. 29—six days before he’s set to accept the GOP nomination—will be the oldest person ever elected to the White House if he wins in November. (Ronald Reagan was only a year older when he was re-elected for a second term.) As the Arizona senator knows well, his age and health will continue to be issues.

Last week, after some delay, McCain allowed a small pool of reporters to examine more than 400 pages of recent medical records. According to the files, he has suffered no recurrence of the melanoma doctors removed from his left temple in 2000. In early 2002, doctors removed an unrelated malignant spot from the left side of his nose. But since then, the cancer has not returned or spread. McCain now undergoes a skin examination at the Mayo Clinic roughly every three months. “His prognosis is good,” Dr. Suzanne Connolly, McCain’s dermatologist, told reporters. “We don’t have a crystal ball, but we have no way to say anything at the present time would preclude him from running for office.”

Some of McCain’s aches and pains are related to war injuries and the torture he suffered during five years as a POW in Vietnam. The records show that he has degenerative arthritis that could prompt a joint replacement in the future. Doctors also revealed that McCain occasionally suffers from “positional vertigo”—which lasts two to five seconds when the senator stands up. Dr. John Eckstein, a Mayo internist who has been McCain’s personal physician for 16 years, called it “harmless.” He said McCain does not suffer from any short-term memory loss, a common problem for men of his age. “He is healthy, he is vigorous, and he can fulfill the obligation of any job, including president of the United States,” Eckstein said.

When asked about his health, McCain generally points to his 96-year-old mother, Roberta, a ball of energy who often joins him on the campaign trail. Staffers emphasize his often grueling schedule: during the primaries, McCain held more than 100 town halls in New Hampshire. He’s known for spending nonstop hours talking to reporters on his Straight Talk Express—his breaks coming when the bus pulls over for a campaign event. This summer, he’s planning to hike the Grand Canyon with his two sons, Jack and Jimmy. In 2006, McCain hiked from the North Rim to the South Rim. “Thirty miles, two days in 115-degree heat … and carrying a backpack as well,” Jack McCain, a midshipman at the U.S. Naval Academy, recently said in a Web interview. “And my dad doesn’t have any cartilage in his knees.”

Barack Obama, 25 years younger than McCain, has repeatedly insisted he won’t make age an issue. Yet the McCain campaign accused Obama of doing just that when the Illinois senator recently said McCain was “losing his bearings” for suggesting that the terrorist group Hamas wanted Obama to win this November. Mark Salter, McCain’s longest-serving aide, called that a “not particularly clever way of raising John McCain’s age as an issue.” The Obama campaign called Salter’s remarks a “bizarre rant.”

A recent ABC News Washington Post poll found that more than two thirds of people questioned would not factor McCain’s age into their vote. The candidate, in any case, doesn’t seem worried that he’ll contrast poorly with a younger rival. Lately McCain’s been the one playing the age card. At a rally last week in Stockton, Calif., he repeatedly called Obama “young man” and raised questions about his judgment and experience. “Don’t get me wrong, I admire and respect Senator Obama,” McCain said, his voice tinged with sarcasm. “For a young man with very little experience, he’s done very well.” It wasn’t the usual self-deprecating routine, but it got some laughs.