Healing is the term which is being used many times in our daily life. Healing from injury, mental healing, etc are some phases of healing. Many times without even noticing we tend to hold on the grudges. The body easily releases the problems but mind never leaves anything easily.
Here, Meena Om, a motivational speaker wrote about the crisis with the mental healing.

"Many a time after deep meditation, or intense healing sessions, people fall ill. That is because sometimes, unknowingly we hold on to certain things in our mind, and during the time of intense healing, the body releases them. So like an erupting volcano, these things get released and body is affected. It is like a strong current of water will throw up the sediments on the floor of the river, to wash it off, or strong floods will break down buildings and uproot trees on the way. Some people are more affected than the others.
In some people initially, small things surface to go first. At other times, the one who is giving healing gets affected by the energy backfires. It is all part of the healing process. It is natural.
This is commonly called a Healing Crisis and if any of these things happen, know that the healing is effective.
The mind should be kept aside while healing as its constant interference impedes the healing flow.....Let it happen, faith and experience are the greatest guides.
Healing should never be confused with 'getting what we want'....because the energy knows what is needed for our growth and will push us towards that direction, not necessarily as per our minds design.
Sohealerandhealee need to have a strong connection besides faith in the process....no one is the 'doer' it is Nature's choice!"