Bonnie Greenwell says in Energies of Transformation:

"This "radical" spiritual experience seems to arise from the deepest roots of the Self, and sweeps one into revolutionary personality and physiological changes. The intensity of this movement has been described in some yogic scriptures as the rush of a divine goddess, Shakti, who is released and charging upward through the system to be reunited with her lover, Shiva, the universal consciousness that awaits her. This demanding goddess, the creatrix and sustainer of the human being, initiates a struggle to free human consciousness from worldly thought, and she produces a wide range of psychic and physiological phenomena, promotes ecstatic experience and agonizing self-confrontation, and demands the reorientation of one's life.

"After centuries of hiding in nearly every culture on the globe as a secret truth, the Kundalini experience is reported more and more frequently among modern spiritual seekers and appears to be occurring even among people who do not follow spiritual practices. When this happens to people who have neither context nor understanding of the correlates between physical and mystical experiences, it can leave them bewildered and fearful, even psychologically fragmented. And when they turn to traditional physicians, psychotherapists or church advisors their anxiety is compounded because western culture offers them no framework with which to integrate the connection between spirituality and physical energy in the body.

"Spiritual awakening need not be a fragmenting nor painful event, although it clearly triggers both physical and emotional transformation. There is ample evidence that the nature of spiritual energy is primarily expanded consciousness and bliss, which is felt consistently once the process has stabilized. It is helpful to view this as a process: a series of actions, changes and functions intended to strengthen the body and character in order to build a vehicle strong enough to hold spiritual energy and insight."


Quoting from The Kundalini Experience by Lee Sannella:

"There have been and still are genuine mystics who have never consciously experienced the psychophysical symptoms associated with the Kundalini arousal. They may know nothing of headaches, burning sensations, painful currents of energy shooting from the feet or the base of the spine up into the head, or of the seven or more wheels of energy in the body. And yet they may experience the unitive consciousness, tranquillity, and bliss. They may even be psychic. If we assume, with Gopi Krishna (1971), that the Kundalini is a fundamental evolutionary mechanism underlying all psychic and spiritual phenomena, then there are two explanations for the absence of physio-kundalini symptoms in many spiritual practitioners and accomplished mystics. The first explanation is that these individuals are relatively free of the kind of obstructions or psychophysical resistances that tend to complicate the Kundalini process in others. The second is that their psycho-spiritual realizations are the result of only a partial awakening of the kundalini power. Both explanations have their supporters, and my personal opinion is that without additional research the matter cannot be conclusively settled." 


In the book A Path with Heart Jack Kornfield says:

"Each of us as a human flower will open in our own unique way in our own particular cycles, we need not direct the specific energies of our body and heart. Our path is neither to desire them nor fear them. The true path is one of letting go. When we cultivate spaciousness, faith, and a broad perspective, we can move through all states and discover in them a timeless wisdom and a deep loving heart."