Kundalini Energy is the name for a specific form of Life Force Energy (Prana) which, according to Hindu religious teachings, is located at the base of the vertebral column (spine) of every human being. In Hinduism, typically in Tantric traditions, it’s believed that Kundalini is Divine Spiritual Energy, strongly associated with feminine, sexual, and creative Shakti energy.
The terms Kundali and Kundalini start to appear in Indian sacred texts, the Upanishads, as from the 7th century BCE. In the Sanskrit language it has different meanings and connotations, such as circular, annular, snake, bowl, rope, ring, water-pot, or coiled. Kundalini is often conceptualized or visualized as a coiled-up serpent (snake).
The active practice with Kundalini Energy comes about around the 11th century CE, and as from the 15th century CE it was also adopted in Hatha Yoga. Later, it became a more mainstream thought in Hinduism, and today it’s a well-accepted concept in modern spirituality, and within the New-Age and Neo-Tantra movements.
It’s thought that Kundalini Energy lies dormant i.e. sleeping in the Muladhara Root Chakra and can be aroused or awakened. The Muladhara Chakra is located at the base of the spine, and is one of the seven primary Chakras, the latter considered the main Prana Life Energy transformation and distribution centers.
By awakening Kundalini Shakti Energy it will be channeled i.e. pushed upwards through the other Chakras (which will be opened and fully activated), along the spine (notably through the Sushumna Nadi, but in some interpretations also through the Ida and Pingala Nadis) up to the Sahasrara Crown Chakra, resulting in a process of Spiritual Perfection, Divine Creativity and Union, Enlightenment and Bliss. It’s also believed that rising Kundalini will give the practitioner certain psychic powers (the so-called Siddhis).
On a spiritual energetic level, it’s thought that when feminine Kundalini Shakti Energy reaches the Crown Chakra, it will be reunited with masculine Shiva Energy (Universal Consciousness or the Divine Ground of all Being), its counterpart, resulting in dissolution of duality and ignorance, and realization of complete spiritual union.
Kundalini Energy can be stirred or awakened by the use of various Yogic practices, such as meditation, Pranayama, Asanas, Acupressure, Mudras, Mantras, and Bandhas, among other techniques. These Yogic activities are often guided by a Guru. Depending on the Yogic lineage, the techniques may focus directly on rousing the Root Chakra, others focus first on the Crown Chakra, and again others on the Navel Chakra (Manipura Chakra).
Whatever the techniques, methods or procedures used, it’s generally believed that, in order to control, handle, and integrate the powerful Kundalini Energy, a preliminary period of purification and strengthening of body, mind, Nadis, and nervous system is necessary to avoid physical or mental injury or even death. Yet, Kundalini can also awaken spontaneously, without any preparation or volition.
In any case, in more ancient times in India, people would take these precautions seriously and would stay for longer periods in ashrams (spiritual retreat centers) to support this preparation practice under the guidance of a Guru before trying to awaken their Kundalini Energy.