Life force, or "pranic energy" is a specific type of energy produced by living things and the biosphere as a whole. This energy is also contained in the blood and is believed by some to be an integral part of the transfer which occurs between a donor and a sanguinarian.

However this “energy” has never been measured by any scientific means until now, which does not mean it is not measurable.

Other types of "energy" are identified, and sometimes differentiated from "pranic energy", these are namely sexual energy, psychic energy, emotional energy, magical energy, negative energy, astral energy, atmospheric energy, ... and many others.