Thyroid disease or eating disorder - how can I tell if I should be worried for a friend?

After a night of drinking (college student) one of my friends passed out cold in a store while standing beside me. She is a model and is beautiful, but she is also extremely skinny as many models are. She does has thyroid problems and had missed about 3 days of her prescription before the party. She says this is why she passed out, she says it has never happened before, and she says there is nothing to worry about.

Still I can't help but wonder if her eating habits are ok - How can I tell if it really is because of her thyroid problem or if she's simply not eating enough.

NOTE: She is my roommates girlfriend, so I don't hang out with her often and they have just started dating so I can't speak to her general eating habits/behavoir.

Just my thoughts but for her to say its because she hadnt taken her thyroid medication for 3 days before the party and that it had never happened before but it was nothing to worry about kind of sends mixed messages --

a. She really does believe its a thyroid problem and is not giving it any more thought

b. She has an eating disorder and is using her thyroid as an excuse but just telling you not to worry thinking that because she says it hasnt happened before you will just let it drop (although if she has an eating disorder she would have her excuses worked out well ahead of time)

c. She was a little freaked by it and trying to deny any problem to make herself feel better and almost convince herself there is nothing to worry about.

d. It happens all the time and she just brushes it off and doesnt want a fuss made

I would probably just watch her eating habbits - she is dating your roommate so you will at times see her eat and then watch to see if she goes to the toilet after eating all the time maybe speak to your roommate about doing the same thing discreatly

u cant tell could have been the drinking/fatigue as well

if she semms to keep on getting skinnier and more frailish bonieshy then have a talk with her and tell her you are worried about her and she is skinny enough!!

I wouldn't worry about it. If she says it was because she missed her prescription, you should believe her. Also, people do sometimes pass out after drinking too much, particularly if they're skinny, because their bodies can't hold alcohol as well.
As you don't really know her that well, there's nothing you can do anyway.

an over active thyroid causes you to eat more and sleep more