Kundalini means hidden potential life energy. It has nothing to do with serpent or anything like that. Kundalini awakening means awakening your hidden potential life energy.
Kundalini awakening is a systematic process of meditation, exercise, pranayam and life style. It is a gradual process. Kundalini awakening releases the external and internal stresses of the body and brings balance in life. There are many stories on Kundalini awakening.
It is generally believe that, at the base of the spine, subtler than the physical body, lies the Kundalini energy, or spiritual potential energy, in a latent form. Regardless of what religious, spiritual, or meditation tradition one follows, the awakening of this energy, by whatever name you call it, is a most innate and essential part of spiritual progress, unfoldment, or realization.
It is balancing the opposite forces Siva male energy and Sakti the female energy. Kundalini awakening is always blisfull rarely painful. Union of kundalini with the thousand-petaled lotus at the top of the head confers bliss that is both physical and spiritual.