(From my free book Spiritualist Basics)
Messages and readings are a form of mental mediumship. The medium raises his or her vibration and allows Spirit communication through in the form of thought. Spiritual healing is a form of both mental and physical mediumship. The healer raises his or her vibration and allows spiritual healing energy to come through. This energy can have positive mental and/or physical effects.
Spiritual healing can reduce pain and suffering, lessen or eliminate symptoms, and promote quicker recovery. The positive healing energy that comes from Spirit through the healer is very powerful and can cure ailments and diseases, oftentimes after medical science has given up and the patient comes to the spiritual healer as "a last resort". But spiritual healing is not a substitute for seeing a doctor.
There should be no contest between medical science and spiritual healers (although you may hear differently). Each have the same goal, which is to restore and promote health. This is not an either-or proposition - no one says you must use one method exclusively over the other. Use them both for your benefit. Don't discredit either one. When you find what works for you go with it. Remember that every body is unique - what helps you may not work at all for someone else.
How does this work? There is a lot of positive energy freely available to everyone in the world. Where does this positive energy come from? Positive thoughts and actions are a source of positive energy. This is true and not just something to be scoffed at. Your thoughts and feelings are energy. This positive energy can be focused, producing positive results. The healer is the pathway for the energy to come through. The spirits around the healer (who are healers themselves) also come through the healer to work on the person in need. The healers in the spirit world are doing the work, the healer is just providing the avenue for them to come through.
How does healing take place? You sit down on a comfortable chair (like a padded piano stool) and just relax. The healer stands behind you and places their hands close to you (they typically touch very little). The healer often works through the aura to promote healing. The healer will start at the top of your head and work down your back and shoulders, then come around the front and work the kneecaps and shin down to the ankle. The healer will work on the areas that need it according to Spirit's directions. The healer will often hold your hands for a few moments and/or talk with you just before the healing is completed. Be sure to say thank you.
Healing can also take place without the person who needs it being physically present. This is called absent healing. When the healer is in a meditative state, the healer can become the pathway for the positive healing energy to flow, which can be sent forth to anyone anywhere.
Healing, like other types of mediumship, can be taught, and some people will find it easier to develop than others. While it is not necessarily required, healers can obtain credentials such as commissions or certifications from various Spiritualist organizations.