Shamanism is the oldest spiritual practice known to humankind with estimates placing it anywhere from 40,000 to 100,000 years old. Shamanic healing techniques are still practiced world wide by both indigenous peoples and others who are called to this work. Sometimes known as spirit doctors or medicine men, shamans view illness as disharmony in a person's life on the spiritual level. This disharmony can lead to mental, emotional, and/or physical illness if left unresolved.