01/28/2013 10:12 am ET

Walking Pneumonia: What Almost Kept Jennifer Lawrence Home From The SAG Awards?

Actress Jennifer Lawrence, who took home the award for female actor in a leading role at the Screen Actors Guild (SAG) Awards last night for her performance in "Silver Linings Playbook," almost missed the whole event because she had "walking pneumonia," according to news reports.

Lawrence, 22, reportedly missed the Australian Academy of Cinema and Television Awards on Saturday because of the lung infection.

But Glamour magazine reported that Lawrence rallied to attend the SAG Awards, even telling E! presenter Giuliana Rancic that "Everyone is scared of me. I'm like, 'I'm fine!'"

Even though "walking pneumonia," also known as atypical pneumonia, sounds like it might be more spreadable than the regular type of pneumonia, it's actually a milder form, WebMD reported. The word "walking" is used because people who have it are often well enough to walk around. This type of pneumonia is most common in younger people, such as children and adults younger than age 40.

The Mayo Clinic reported that "walking pneumonia" is caused by bacteria that produces less severe symptoms, and usually antibiotics aren't needed to treat it because symptoms will go away on their own. The A.D.A.M. Medical Encyclopedia reported that the bacteria Mycoplasma pneumonia, Chlamydophila pneumoniae and Legionella pneumophila are often responsible for this form of pneumonia.

Symptoms of "walking pneumonia" include chills, cough, shortness of breath and fever, though other, less-common symptoms include headache, sweating, muscle aches, chest pain, confusion and loss of appetite, according to the A.D.A.M. Medical Encyclopedia.

WebMD reported that symptoms usually appear anywhere from 15 to 25 days after the person was first exposed to the bacteria. A patient is usually contagious for about 10 days or fewer, though usually it takes being in close contact with an infected person for prolonged periods of time in order to catch it.