When the body has been freed of an intolerance or allergy to which it has been exposed in the past, any of the stored substance will be released from the cells and begin to recirculate through the body until it can be eliminated from the body. The odd headache, sore throat, sinus congestion, tired or lethargic feeling, aches and pains or even nausea (healing crisis) are all usually signs of the body regenerating new cells and cleansing itself. A healing crisis can start the day after the session up to 3 weeks in some cases, and may last from 1 to 28 days.