Symptoms of shamanic experience below are symptoms I and others I've known have experienced:
* overwhelming, sudden fatique
* almost unbearable body cramps
* heart palpitations
* intense sweating or intense cold
* kundalini energy up the spine and in the root chakra area
* strong pressure in the crown chakra
* frightening fits of sudden coughing and phlegm in the throat - throat chakra challenges
* loose bowels
* breathing difficulty
* feelings of panic and wildness, as if losing grip on reality
* dreams of a spiritual nature and horrible nightmares
* trouble sleeping
* trouble waking up
* confusing flashes of different people when eyes are closed
* feelings of being trapped in other dimensions and unable to return
* free-falling into nothingness when eyes are closed
* extreme awareness of cells and bodily functions
* intense empathic connection to others
* inability to separate self from others
and other symptoms I've probably forgotten by now. In other words, anything the body can experience happened to me at some time or another during periods of shamanic initiation.
Not to worry....
If the above list of symptoms causes fear, I understand. If I'd been handed a list before my own shamanic experiences began, I'd have freaked out big time. Luckily, I didn't know until it was too late and I was soul-deep in the experience. I'm sure that was a perfect unfoldment, as is your finding a list of symptoms beforehand will be perfect for your journey. I believe there is an infallible wisdom to the universe and that one will never be initiated into something their soul did not invite, regardless of how challenging it may seem to the ego self at the time.
I would not actively seek out shamanism. I did not seek it out, at least not consciously but I always sought impeccability and integrity and realize now that this was a door-opener for the other experiences. I sometimes seemed to be just sitting there, praying or singing or sometimes just being, when the shamanic intiations came. Even when preceded by all kinds of signs and physical symptoms, they seem always to catch me off guard, in the ego sense.
Spiritual Health Disclaimer: Though Shamanic Experiences may present themselves with accompanying physiological changes, you should see a doctor if any physical symptom you are having warrants that. Be wise with your health.