HOUSTON - When presidential candidate Hillary Clinton recently became ill at a public event, we learned that she was battling pneumonia.
Leaving a 9/11 service Sunday, Clinton stumbled and was helped into a van. Hours later, leaving her daughter's apartment, she said she felt fine.
Houston Methodist pulmonologist, Dr. Lisa Kopas says, walking pneumonia, like what Clinton has is a common and contagious infection.
"Walking pneumonia just means a community-acquired pneumonia that's less severe," Kopas said.
She says Clinton would have been contagious on the campaign trail during any time she was not on antibiotics.
"Obviously that's how she got it, from doing the kissing the babies and shaking hands and so forth and being in large crowds and so she would catch it from someone and yeah, unfortunately almost all cases of pneumonia will have some short period of time before they're diagnosed where you will have a period of being contagious," Kopas said.
Clinton's doctor says she "was put on antibiotics and advised to rest and modify her schedule."
"I would expect most patients to start feeling fine in a week or two," Kopas said.
Anyone can get pneumonia, although kids under 5, those over 65 and anyone with compromised immune systems are most susceptible to developing complications from it. The Centers for Disease Control and Prevention recommends people in those groups to get a vaccine to protect them from pneumonia.