Energy medicine is a branch of alternative medicine based on a pseudo-scientific belief that healers can channel "healing energy" into a patient and effect positive results. Practitioners use a number of names including various synonyms for medicine (e.g., energy healing) and sometimes use the word vibrational instead of or in concert with energy. In most cases there is no empirically measurable energy involved: the term refers instead to so-called subtle energy. Practitioners may classify practice as hands-on, hands-off, and distant (or absent) where the patient and healer are in different locations. Many schools of energy healing exist using many names: for example, biofield energy healing, spiritual healing, contact healing, distant healing, therapeutic touch, Reiki or Qigong.