How Much Does the Public Need to Know About Hillary Clinton's Health?

After US presidential candidate Hillary Clinton left a 9/11 memorial service early on Sunday, her campaign team revealed she has pneumonia. Whatever you personally think about a presidential candidate suffering from a lung infection, the news has highlighted an perennial debate in politics: when it comes to a politician's health, how much does the public have a right to know?

It seems obvious why the public would want to know about an elected official's health status: to feel informed about whether or not that person is fit to hold office. It's also pretty clear why politicians might not want all of their health details laid bare: there's stigma and misunderstanding around a lot of health issues, particularly mental health, and how fit or unfit a person is for office is largely subjective.

"Suffice it to say that there's always been this tension for full disclosure of health information," said Dr. Robert Green, the director Genomes to People, a research program between Brigham and Women's Hospital, Broad Institute, and Harvard Medical School.

That tension is perhaps most obvious in a 2004 Gallup poll that asked Americans about whether politicians should disclose health records. Ninety-six percent of respondents said a president's health is somewhat or very important to his or her ability to be a good president. But 61 percent then said they believe a president has a right to keep medical records private, even as 84 percent said the president should be required to get yearly medical exams.

"This just really gets to the fact that all of this is really conflicting and subjective," said Geoffrey Skelley, an analyst at the University of Virginia Center for Politics. "I think that confirms that, when talking about what should be out there for the public, it's really difficult to nail down what is pertinent."

We've had many elected officials who have openly disclosed health statuses: President Franklin D. Roosevelt, of course, had polio and often used a wheelchair. Mike Huckabee, former Governor of Arkansas and repeat presidential hopeful, is diabetic. Tom Duane, a former New York State Senator, is HIV positive.

Maryland Governor Larry Hogan went through 18 weeks of intensive chemotherapy last year after being diagnosed with non-Hodgkin's lymphoma. Skelley told me most pundits expect Hogan to run for reelection, and the governor's approval rating is the highest the state has seen in decades.

But when you look at historical examples, the line between what makes a candidate fit to serve or not often seems to be the line between mental illness and physical ailments. Green cited the case of Thomas Eagleton, who in 1972 was replaced as George McGovern's presidential running mate after it was revealed Eagleton suffered from depression and had undergone electroshock therapy.

"With things like depression, there are a lot more views among the general public—which may not be medically accurate—of what's associated with that and the connotations of it," Shelley told me. "It's a lot tougher for a politician to reveal, especially if they're actively running."

There are some small signs of changing views on this front: last year, a Canadian member of provincial parliament went public with her struggles with depression, after she had undergone treatment. But for many Americans, the highest position in the country is still too high of stakes to accept any medical issue, whether physical or mental. That means mysteries over the commander-in-chief's health—like whether President Ronald Reagan already had Alzheimer's disease while still in office or if President John F. Kennedy knew he had Addison's disease—may continue to be standard fare.

It may also explain why Hillary Clinton's campaign didn't immediately disclose her pneumonia (she was reportedly diagnosed last Friday) until after a public event required an explanation. Now, Republican candidate Donald Trump has pledged to publish the results of a recent physical, and Clinton's team has said they'll release more detailed health records of the candidate to show pneumonia is her only ailment. Even with such a long history of politicians with various health statuses, there's still an appetite to verify a candidate's health, whether it impacts their ability to hold office, or not.