We did have a
post earlier from a teacher asking about a student who had nausea while in Snail pose. This student was quite overweight and probably suffered high blood pressure. Your situation sounds quite different, but you could ask about her blood pressure.
If your student continuously feels nausea, she really should go see a professional health care provider to make sure there is nothing serious going on. If her doctor finds no pathology, then we can speculate that there is something in the practice affecting her.
The abdomen contains our "second brain" - the enteric nervous system. Connecting this brain to your higher up brain is the vagus nerve. The vagus nerve controls many aspects of our autonomic nervous system and when we stimulate it, as we do in our yoga practice, it can affect us in a variety of ways. She may over stimulating the vagus nerve through physical compression of the abdomen in her forward folds, or through compression of the meridians associated with the spleen and stomach. Nausea is associated with the stomach/spleen meridian lines, as is the emotion of worry (fear is usually associated with the Kidneys and anger with the Liver.)
However, there may be another potential cause: she says that she is not feeling compression in the belly in these poses and has not eaten, so maybe the problem is somewhere else. The vagus nerve gets its name from the Latin "wandering" - it wanders everywhere in the upper body, including as it descends from the head downward. Sometimes compression of the vagus nerve can come from the neck. Next time your student comes into these forward folds, ask her to experiment with holding her head up, rather than dropping it down. See if by not flexing the neck she avoids these sensations. She can try resting her head into her hands or onto a block or a bolster.
Let us know how it goes!
Cheers
Bernie
