Most of the therapies will produce some level of healing crisis which may last upto 24-48 hours afterwards.  
These are perfectly natural processes the person may go through after a therapy some may notice a new symptom or a symptom already being experienced maybe slightly exacerbated.  
Some of these maybe experienced as : Fatigue, lethargy, cold or flu like symptoms, emotional, tearfulness, stomach upset and headache. You may be very lucky and experience a deep state of relaxation or nothing at all.