If an older person went to the doctor with a fever, chills, body aches, and a cough, what would the doctor most likely suspect the person has?

The correct answer is influenca, more commonly known as the flu. Commonly, there's high fever and and a runny nose, but it can be much much worse, sometimes even causing death. Many people vaccinate against the flu before the flu season so as to avoid getting ill because it can be a bother.

Few days to several months depending on the severity of the stroke ;