What can happen during a Breathwork session?

What are some of the things that we can find out in a Breathwork session? 

According to one of the leaders in Breathwork, Stanislav Grof, the main categories of experience are;

1. Sensory experiences  - a Breathwork session often starts off feeling very physical in nature - we can feel a build up of energy - this can be subtle or big movements.
2. Biographical experiences - feeling fully and engaging with feelings - noticing experiences of omission (what we didn't get) and commission (what happened to us).
   
3. Perinatal (in the womb) experiences - nurturance / unity, victimisation, struggle, then completion
4. Transpersonal experiences - those beyond our own ego - past-life, ancestral memory, identifying with archetypes.