What’s really going on with Hillary Clinton’s health? Many people distrust the little bit of information the Clinton campaign has put out.

Clinton’s physician, Dr. Lisa R. Bardack, apparently diagnosed the former secretary of state with pneumonia on Friday — news that was only released after Clinton’s dramatic early departure on Sunday morning from a Sept. 11 memorial ceremony in downtown Manhattan. The diagnosis follows years of other significant health issues for Clinton, including a major concussion she suffered in 2012.

[lz_jwplayer video=”w6EpG3F1″ ads=”true”]

The Clinton campaign has said Hillary was evaluated and diagnosed on Friday amid a busy campaign schedule, but that they chose to keep the diagnosis to themselves because they didn’t think it was “that big of a deal.” The campaign has not clarified whether the diagnosis is viral or bacterial.

They maintain nothing else is wrong with Clinton other than the pneumonia and her allergies. But Hillary Clinton herself just said she “was supposed to rest for five days” — advice she clearly didn’t take.

Pneumonia is an infection of the lung — the lungs fill with fluid and make breathing difficult. Pneumonia disproportionately affects the young, the elderly, and the immunocompromised, as the American Thoracic Society and others note. In older adults, often a sign of pneumonia is a change in how well they think — confusion or delirium is common.

Also — and this is key — patients with pneumonia often need to be hospitalized or even go to the intensive care unit (ICU). After developing pneumonia, it often takes 6 to 8 weeks until a patient returns to a normal level of functioning and well being.

Related: 7 Hillary Health Episodes

So, of course — one of the smartest places for Hillary to go after her legs went out from under her on Sunday was her daughter Chelsea’s apartment, where Hillary’s young grandchildren live. Walking pneumonia or otherwise, the disease is communicable, with infants being among the most at risk of contracting the disease.

Bacterial pneumonia is not ordinarily contagious like the flu, said Dr. Amesh Adalja, a board-certified infectious disease physician at the University of Pittsburgh. “Most bacterial pneumonias begin with bacteria colonizing the upper airway — at this stage nasal colonizing bacteria can be passed from person-to-person but don’t always necessarily lead to pneumonia. Viral pneumonia, on the other hand, can be contagious as the respiratory viruses that cause it can spread through coughs and sneezes.”

Who do you think would win the Presidency?

By completing the poll, you agree to receive emails from LifeZette, occasional offers from our partners and that you've read and agree to our privacy policy and legal statement.

If she is on antibiotics, and pneumonia truly is her diagnosis (though we still don’t know which kind was diagnosed) — “the most important aspect of recuperation from bacterial pneumonia is gaining access to antibiotic therapy,” Adalja told LifeZette.

“The most important aspect of recuperation from bacterial pneumonia is gaining access to antibiotic therapy,” said one physician.

“My biggest concern is what did not happen,” Dr. Gerard Gianoli, a physician in private practice in Covington, Louisiana, and a faculty member at Tulane University School of Medicine, said in an interview on “Newsmax” on Monday.

“She did not go to a hospital. I guarantee you if I was in that motorcade, regardless of what Mrs. Clinton said, I would have brought her to a hospital. Unless she’s had other episodes like this and this is a recurring thing that they’re used to, this was a very concerning event,” said the doctor.

“She was just started on a new antibiotic. We don’t know if she was having an anaphylactic reaction to the antibiotic — bringing her to her daughter’s apartment could have been a death sentence to her,” he added. “I have some concerns about whether she’s allowing the doctors to help her or whether she’s just ignoring their advice, but this is not what you typically see from someone who has pneumonia.”

Related: Hillary’s Allergy to Transparency

There are still so many other unanswered questions about Hillary Clinton’s health. Does she have other underlying medical conditions that aren’t being addressed or revealed? How are the antibiotics she’s taking reacting with the other medication she’s taking? (She takes Coumadin, a blood thinner). Has she felt faint or dizzy on other occasions that haven’t been revealed? And why aren’t more members of the media pressing for more information? Are we just on the tip of the iceberg here?

Here is some other information about pneumonia worth noting:

1.) Older people have a higher risk of getting pneumonia, and are more likely to die from it if they do, according to the American Thoracic Society. For U.S. seniors, hospitalization for pneumonia has a greater risk of death compared to any of the other top 10 reasons for hospitalization.

2.) Pneumonia is the most common cause of sepsis and septic shock, causing 50 percent of all episodes.

3.) While successful pneumonia treatment often leads to full recovery, it can have longer term consequences. Adults who survive pneumonia may have worsened exercise ability, cardiovascular disease, cognitive decline, and quality of life for months or years.