Holistic Medicine is defined by the Canadian Holistic Medical Association as follows.

Holistic medicine is a system of health care which fosters a cooperative relationship among all those involved, leading towards optimal attainment of the physical, mental emotional, social and spiritual aspects of health.
It emphasizes the need to look at the whole person, including analysis of physical, nutritional, environmental, emotional, social, spiritual and lifestyle values.
It encompasses all stated modalities of diagnosis and treatment including drugs and surgery if no safe alternative exists.
Holistic medicine focuses on education and responsibility for personal efforts to achieve balance and well being.
Suzan Walter, President of the American Holistic Health Association (AHHA), put together an excellent summary of the principals of Holistic Health.
The summary can be found on the AHHA Web Page. For those unfamiliar with Holistic Medicine, I strongly encourage reading this short summary.
Other Terms Associated with Holistic Medicine
- Alternative Medicine is often used by the general public and some healthcare practitioners to refer to medical techniques which are not known or accepted by the majority ""conventional"" or ""allopathic"" medical practitioners (usually M.D.'s).
Such techniques could include non-invasive, non-pharmaceutical techniques such as Medical Herbalism, Acupunture, Homeopathy, Reiki, and many others.
However, the term Alternative Medicine can also refer to any experimental drug or non-drug technique that is not currently accepted by ""conventional"" medical practitioners.
As non-invasive, non-pharmaceutical techniques become popular and accepted by large number of ""conventional"" practitioners, these techniques will no longer be considered Alternative Medicine.
Alternative Medicine refers to techniques that are not currently accepted by ""conventional"" practitioners, but what is currently accepted is quickly changing. Even the definition of ""conventional practitioners"" is quickly changing.
Therefore, techniques that are now considered part of Alternative Medicine will soon be considered part of ""conventional"" medicine.
The terms Holistic Healing and Holistic Medicine are slightly more stable than Alternative Medicine and are therefore preferable.
- Complementary Medicine…
…is often used by ""conventional"" medical practitioners to refer to non-invasive, non-pharmaceutical techniques used as a complement to ""conventional"" medical treatments such as drugs and surgery.
The term implies that ""conventional"" medicine is used as a primary tool and the non-invasive, non-pharmaceutical techniques are used as a supplement when needed.
In many cases, properly chosen non-invasive and non-pharmaceutical healing techniques plus properly chosen lifestyle changes can completely and safely heal both acute and chronic illnesses.
In other cases, ""conventional"" medicine is only needed in emergencies or when the safer non-invasive, non-pharmaceutical methods fail. In some cases ""conventional"" medicine will be a major part of a Holistic Healing Plan, but in some cases it is not needed at all.
- Natural Healing…
…usually refers to the use of non-invasive and non-pharmaceuticals techniques to help heal the patient. When most people use the term Natural Healing, they are usually referring to physical healing techniques only.
(Source: Holisticmed.com)