Airlines don’t want passengers onboard who will spread disease or cause a diversion. Flight crew aren’t always best-positioned to judge this, but they’re in a position where they have to. And airlines often do things out of an abundance of caution, although nearly every time you hear that phrase it’s a cover for stupidity.
Beth Evans was flying Emirates from Birmingham in the U.K. to Dubai. She told her boyfriend about her cramps. A flight attendant overheard the conversation and started quizzing her about it.