Gen. David Petraeus, the head of U.S. Central Command, apparently fainted while testifying before the Senate Armed Services Committee. Near the end of a tense back-and-forth with Sen. John McCain (R-AZ) about Afghanistan war timetables, Petraeus slumped over in his seat. (Watch Petraeus fall unconscious.) After a brief break, he proclaimed himself fine, if undernourished. Senators were worried enough to postpone the rest of the hearing, however. Here's a brief look at what happened:

Is Petraeus ill?
Not generally. He was treated, successfully, for early-stage prostate cancer in 2009, and a fellow soldier accidentally shot him in the chest in 1991. But Petraeus is famously obsessive about his physical fitness and known for his marathon running. He "has never fainted before today," says his spokesman, Col. Erik Gunhus, who blames simple fatigue, noting that Petraeus just returned from a weeklong visit to London and Jordan.

Was it something McCain said?
No, despite jokes to the contrary. "It wasn't Sen. McCain's questions," Petraeus said. "I just got dehydrated." It would be "understandable that there might be some strain on him, though," says David Graham in Newsweek. "Senators were grilling him about President Obama's plan to start withdrawing troops from Afghanistan starting in July 2011," which some call "too aggressive." Slate's Fred Kaplan sees the fainting spell as a "grim metaphor" for how the war's going.

Could it be something he ate?
According to Petraeus, it was more something he didn't eat: Breakfast. In fact, the famously ascetic general reportedly eats only one meal a day and sleeps four hours a night.

Does this happen often?
Sen. Carl Levin (D-MI), who chairs the Senate Armed Services Committee, says he's never seen any witness collapse during a hearing. There is a long, storied history of public figures fainting, however: The first President Bush dramatically slumped over into the lap of the Japanese Prime Minister during a state dinner in 1992, while his son, less impressively, once fainted in 2002 while eating a pretzel and watching a football game.

So why did Petraeus' fainting get so much attention?
Along with being the chief strategist for the wars in Iraq and Afghanistan, Petraeus is the most popular military leader of his generation. He's also rumored to have presidential ambitions, despite his frequent denials, and "health issues are always important" for political candidates, says Rutgers political science professor Ross Baker. "People, particularly those who come out of a non-political background, are somewhat of a mystery, and people want to know more about them."

Sources: Politico, The Hill, Wonkette, Newsweek, Fox News, Washington Post, Runner's World, NowPublicSlatePolitics Daily