The Energy Body
Tantrics consider the human body to be a microcosm, while the entire Universe (or Multiverse) is the macrocosm. In other words, the human body is a representation, or a map, of the whole of reality.
The energy, or energetic, body of a human being corresponds to the bio-energetic level of the Universe.
Just as the physical body must be purified, strengthened, and made ready for intense Tantric practice, the energy body must also be prepared. Any restriction to the free flow of energy can cause problems for Tantric practice.
The energy body has an anatomy, which correlates with the anatomy of the physical body. Detailed descriptions of the energy body can be found in the chakra systems of India, Tibet and China, the meridian system used in acupuncture and Chinese medicine, and modern scientific investigations of the nervous, lymph, and fascia systems. The movement of "energy" in the energy body has been correlated with blood flow, lymph flow, and hormone and enzyme activity. While "energy" remains a scientifically loose term, it is still a useful concept for the Tantric practitioner.
Most modern Tantra is based on translations in English of a small number of Tantric documents in the late 1800s and early 1900s. Included in this corpus was a description of a system of seven major chakras, with many secondary chakras, and thousands of energy channels, knows as nadis. The seven major chakras are arranged vertically, from the perineum to the crown of the head.
The core purpose of Tantric practice is to raise energy from lower chakras to the crown chakra.
The energy body in Tantric sex
The energy body is a vital part of Tantric sex. No matter how enjoyable sex may be at a physical level, if neither party is focusing on the energy body level, then it cannot be described as Tantric sex.
The core purpose of Tantric practice is to raise energy from lower chakras to the crown chakra. In Tantric sex, the practitioner deliberately inflames sexual energy, which is primarily located in the first and second chakras, and then moves the energy upward, in a process known as "sublimation".
Physical orgasm can trigger a rush of energy from lower chakras to higher chakras. Tantrics seek to consciously trigger this movement, with or without physical orgasm. If a person is not ready to experience higher levels of consciousness, this rush of energy can cause them to momentarily lose consciousness. With sufficient preparation and practice, the Tantric learns to remain aware, and to experience the altered states of consciousness. These higher states of consciousness are correlated with high levels of energy in the higher chakras.