Reiki is a energy therapy which come from Japan. The practitioner will assist your body energetic vibrations to balances and harmonize.
Like you will do with a musical instrument, you can adjust your body vibration to an harmonious state.

Laying of hands or at a distance, the effect of Reiki natural energy therapy are very impressive.

The thing that i have been the most impressed with Reiki is how easy is that method for the results it gives. Easy to learn, easy to practice and efficient result even with what is considered as chronic illness.

The best analogy that i seen is that a Reiki session is like a week at the sea. You feel so better and regenerated that it speaks for itself.
Sometime the experience can be emotional, feeling better is usually directly related in healing some wounds of the past.
What makes Reiki unique from other energy therapy is that the body takes what it needs. We don’t direct the energy here. You cannot go for a Reiki treatment and say  “I want to clear this from my body”. If you want to work on a specific issue you might be more interested to work with energy therapy.
The reason for that is that we never know all the factor that lead to a disease, in term of energy, everything count: The thought quality of the patient, his alimentation, his living environment, the thought quality of the people around this person, etc…
Sometime the people may be ready to release an all emotion, sometime not.

The emotion affect the physical health, the mental affect the emotional health, etc…

We can consider an emotional trauma as a tumor. If the tumor is very big, it may takes many sessions to free the body of the dead cells. release all in one will just result in obstructing the kidney and liver.
The healing has to be supportive and the big emotional traumas will be diminished a little by little, until the person is ready to expulse it all.
Considering the physical health, Reiki is not a practice for immortality but It assists people to get a better life.