What is "the vapors?"?

Question

My AP NSL teacher asked me if I had the vapors and I started laughing...what does it mean?

Answer 1

I think she was asking whether you were feeling depressed.
Or possibly whether you were being hysterical.

This is the dictionary entry I found:
1. Exhalations within a bodily organ, especially the stomach, supposed to affect the mental or physical condition. Used with "the".
2. A nervous disorder such as depression or hysteria. Used with "the".>

Answer 2

A Victorian belief that emanations from bodily organs (such as the stomach) could affect the physical and mental condition of people, especially women. Vapors were often blamed for women fainting, although fashions that included binding women's bodies so tight that they could barely breathe would seem to be a more likely cause.