The average age of members of the U.S. Senate is older than it has ever been, according to Senate Historian Richard Baker. For many senators, advanced age is starting to show, raising questions about their ability to govern.

Until his retirement last month, former majority leader Bill Frist, R-Tenn., a noted heart surgeon, was being consulted for informal medical advice by two dozen of his colleagues -- more than 20 percent of the Senate, according to a former leadership aide. They went to Frist complaining about a host of illnesses and chronic maladies, most related to aging.


Among them were Sen. Pete Domenici, R-N.M., who flew on Frist's jet for private consultation and treatment at the Frist Clinic in Nashville, according to Senate sources.

The average age of the 100 senators is 62, up from 60 in the last Congress. Among the new Democratic committee chairmen, it is 69. And, of the five longest-serving senators, three are there today. Including the grand-daddy of seniority, Sen. Robert C. Byrd, D-W.Va., 89.

As far as illnesses, at least 10 senators have fought various cancers or suffered severe injuries. Sen. Tim Johnson, D-S.D., remains hospitalized here for a brain hemorrhage suffered last month. And others deal with chronic and debilitating infirmities.

In the past, the clubby atmosphere of the Senate provided cover for its frailest members. No longer. Today, a senator's smallest stumble, nap or memory lapse gets instant and widespread public exposure online through blogs and videos posted on YouTube and other social-networking Web sites. (See related story.)

Few senators will talk publicly about their own health problems or those of their colleagues. But many sought counsel from one of their own, Frist. He offered informal and discreet medical advice to his colleagues and some spouses during his 12-year tenure, a former Senate leadership aide said.

"You would be surprised by the people who sought his advice" on health-related issues, said the former aide. "There was a steady flow of people in and out of the office." Frist declined to comment.

If the president appears in public wearing so much as a dime-sized bandage, the press demands, and usually gets, a detailed medical explanation from the White House. No one questions the public's right to know precisely and in full about the physical health and mental well-being of the commander in chief.

Closer to home, Americans routinely face the wrenching tasks of taking car keys away from elderly parents who can no longer drive safely, or delivering the necessary (but unwelcome) news that it's time for an infirm parent to move into assisted care.

Yet suggestions that an enfeebled senator consider retirement haven't been broached, even considering the distressing example of the late Sen. Strom Thurmond, R-S.C., who spent the final year of his term, at age 100, in and out of Walter Reed Army Medical Center here.

The issue is increasingly relevant today, considering the current Senate's advanced age, particularly among its leaders. Byrd, Edward M. Kennedy, D-Mass., and Daniel Inouye, D-Hawaii -- Numbers 1, 3 and 4, respectively, among the longest-serving senators -- have been in the Senate more than 40 years each. And each chairs an important committee at an age when most people are retired: Byrd holds the gavel at Appropriations, Kennedy, 74, at Health, Education, Labor and Pensions, and Inouye, 82, at Commerce, Science and Transportation.

"People don't like to talk about age," said Boston University history professor Julian E. Zelizer. "It's not a political taboo, but a cultural one. We're respectful of the elderly." To raise the issue in a political context, Zelizer continued, is even more fraught with difficulty because any discussion of the office-holding elderly portends a conversation about that which is even more awkward -- mortality. The subject of death is especially acute in the Senate, "where individuals matter," as Zelizer diplomatically put it.

The impact of a single senator's health was underscored when Johnson, 60, suffered a brain hemorrhage in mid-December. He is recovering in a Washington hospital, and physicians have said it may take months.

This was big news, in part because of how suddenly a relatively young senator was stricken, but more importantly because of the potential political fallout. Should Johnson be unable to complete his six-year term, which ends in January 2009, South Dakota Gov. Mike Rounds, a Republican, would likely fill Johnson's seat with a GOP appointee, thus taking control of the Senate out of Democratic hands.

Johnson is receiving several hours of speech and physical therapy a day, and his office has issued repeated statements that he is on the way to a full recovery. Johnson has hired a strategist to help oversee his re-election effort next year, answering, at least for now, the question of whether he plans to run again. (Majority Leader Harry Reid, D-Nev., appointed Sen. Barbara Boxer, D-Calif., to take over Johnson's gavel at the ethics committee in Johnson's absence.)

Johnson's illness also reinforced the delicate topic of whether a senator is mentally fit to serve. Such was the question when Thurmond finished his tenure.

After moving into Walter Reed following several hospitalizations, Thurmond stopped presiding over the Senate, and at committee hearings typically would only read verbatim remarks prepared by his staff. On the floor, his fellow senators would "come pay homage" to their nonagenarian colleague as he sat waiting to vote, said Rutgers professor Ross K. Baker.