Poor thing.
Heart disease and blood pressure problems can be linked to obesity but, I know a few people that are very thin and super athletic that have had emergency open heart surgery. So, lets not even try to speculate why she is ill.
I just hope she takes care of herself first. Yes, the shows are important. Singing is important but, she really should take all the time to rest.
I wish her well.
http://www.thestar.com/entertainment/article/656319