Reiki can be used to help everything and anything that needs healing. That can be physical, mental, spiritual, or emotional -- past, present, and the future. You can and should use your intuition for using Reiki.
Reiki is both powerful and gentle. In its long history of use, Reiki has aided in healing virtually every known illness and injury, including serious problems like cancer and heart disease, as well as skin problems, cuts, broken bones, headaches, colds, sunburn, insect bites, insomnia, lack of confidence, etc.
In Oriental cultures, healing disciplines like Reiki may be applied to healthy people as a preventative method. However, Reiki may also be used to assist you in returning to a state of good health.
Many healing miracles with Reiki have occurred and there are many books and articles that have documented this, but usually Reiki is not a magic bullet. It's a healing modality that should be used in conjunction with other healing modalities to help heal and change your life. The types of healing modalities used with Reiki depend on your needs and circumstances.
Reiki can also be used to relieve stress, to overcome unwanted habits, to achieve desired goals, and to protect from harm. All living things will respond to Reiki, including animals.
