The astral body is a hypothesized spiritual counterpart to the physical human body that is said to exist on a different plane.
According to yogic philosophy, humans have three bodies -- the physical, the astral and the causal -- which, together, are the vehicle of the soul. The astral body is more subtle than the physical body and it contains prana (life force), the senses and the mind.
In yoga, it is the astral body which contains prana and the the system of nadis (energy channels) that carry prana. These are sometimes known as astral tubes.
Plato first philosophized about the concept of an astral plane, containing the planetary heavens, and it is in this astral plane that the astral body is said to reside. The term was later used by Theosophists in the nineteenth century and by neo-Rosicrucians.
The astral body is associated with imagination, emotions and desires, which it conveys to the physical body. During sleep, death, or through drugs or any other loss of consciousness, the astral body is said to separate from the physical body and, in its absence, no pain or sensation can be felt.
The astral body is associated with notions about an afterlife as it is the posited vehicle for carrying the soul from the physical body into higher realms. It is also said that the astral body is the body through which humans may experience dreams, visions, out-of-body experiences and astral projection.
Awareness of the astral body is believed to be stimulated by meditation, shamanic practices, lucid dreaming and certain drugs. Some say that it can be seen as an aura of constantly changing colors swirling around the physical body. It is als described as being like ether and attached to the navel of the physical body by a silver cord.