I've had pneumonia and it damned near killed me.
In October of 2011 I went to bed with the expectation of working another twelve hour day driving a taxicab in Minneapolis. Roughly a month later I woke up in an ambulance while being transferred from Fairview Southdale hospital in Edina to a long term care facility in Hopkins. And I have no memory at all of the first month hospitalization. And I have no memory at all of the heart attack that left me clinically dead for 40 minutes and nearly killed me.
So when Hillary Clinton is claiming that her very apparent health problems are due to pneumonia I'm not about to believe her.