Kundalini is a Sanskrit term from ancient India that identifies the arising of an energy and consciousness which has been coiled at the base of the spine since birth, and is the source of the life force (pranic energy, chi , bio-energy) that everybody knows. Yogic science suggests that this energy triggered the formation of the child in the womb, and then coils 3 ½ times at the base of the spine to hold the energy field in stasis until we die, when it uncoils and returns to its source.
Kundalini may unravel and arise from the base of the spine (or sometimes from the feet) due to spiritual practices, or in response to life events, and when this happens it may move gradually, uncoiling like a snake, or quickly and explosively, into the gut, the heart or the head. This event can be startling and chaotic, frightening or blissful, and it usually triggers months and years of new sensations and changes in the person who awakens it. It may feel like the body’s wiring has moved from 110 to 220, and it takes time to adapt to it. It is understood in the eastern tradition to be a significant adjunct to spiritual realization, but it is rarely recognized as such in western traditions, although Christian mystics have often been said to have intense energetic or physical problems.
It is possible to find acknowledgement of this spiritual movement in many yogic and tantric traditions, Tantric Buddhism, Taoism, gnostic mystical tradition and some Native American teachings, and indigenous societies. An image of a rising snake in the body signifies its existence in the esoteric art of many cultures. The capacity to intensify and raise energy in the body has been explored for thousands of years. It is a natural human potential.
Source: Kundalini Guide | http://www.kundaliniguide.com/what-is-kundalini