In China it's called chi, meaning life force. In India it's referred to as prana or shakti. In Japan it's ki. In the Khalahari desert, the aboriginal Kung call it num. In the Christian tradition it's known as the Holy Spirit. In the Jewish mystical tradition, it's known as nefesh.

The concept of a radiant subtle energy and spirit underlying the physical world is almost universal. So is the idea that this energy can be harnessed for profound transformation and healing. More than two thousand years ago, the Chinese created acupuncture, a system that uses needles to influence the flow of chi through the body's energy meridians. In India mystics have been transmitting prana or shakti from master to student, changing consciousness, for at least as long. The Khalahari Kung raise num through ecstatic all-night dances, in which they perform healings and receive visions.

These and other spiritual traditions perceive subtle energy as affecting both the mind and the body. For instance, if you improve the flow of chi or shakti to a person's physical heart, that person may also feel more "open-hearted" or compassionate. If you are suffering from a liver ailment, part of the cure in Chinese acupuncture or subtle energy healing might require you to release stored-up anger so your energy can flow. If you have a hypo-active thyroid, you may need to work on speaking up for yourself to open all the energy channels.

If this all sounds too fantastical, I can relate. When I began investigating subtle energy and healing more than a decade ago, I was a skeptical journalist. I didn't know if subtle energy could exist. It was quite a shock to discover that not only did it exist, but that the energy--something I couldn't then see and scientists still can't directly measure--could nonetheless have a profound effect on my life.

The first experience I had with subtle energy didn't make me a believer. For a magazine assignment, I sat in on a healing by Barbara Brennan, a one-time NASA scientist turned energy healer. To begin she asked the 150 students in her sophomore class at the Barbara Brennan School of Healing to focus and enhance the spin of their chakras, vortexes of energy located along the spine. These chakras are said to feed energy to organs and glands in the body and also regulate our emotions, thoughts and beliefs. Looking and feeling like energy whirlpools, they bring in energy and information from the environment.

The class started, in unison, with the first chakra, located at the base of the spine and climbed to the second chakra, located at the navel, then on to the 3rd chakra at the abdomen and the 4th chakra, at the heart. But I couldn't see or feel anything. Then Brennan had everyone bring his attention to the fifth chakra. All of a sudden, my throat began burning up. I thought I was going to choke to death. Then I recalled that the fifth chakra was located at the throat. With that thought, I could breathe again. Afterwards, the teacher sitting next to me told me that the "energy" had hit a "block" in my throat. I didn't buy it.

Later, to test the theories, I tried a few sessions with a graduate of Barbara Brennan's healing school. It didn't seem like much happened and I decided my fifth session would be my last. At that appointment, the healer told me that I had an energy blockage in my throat in the shape of "quills." (Blocks in my throat, again!) Furthermore, she asserted that the quills were there because of "barbs" that had been thrown when I tried to "speak my truth." As you might imagine, this sounded ridiculous to me. I lay down on her healing table with a "show me" attitude. When she got to my neck, even though she didn't touch me, I felt the most irritating sensation. The power of suggestion, no doubt.

A week later, my brother and I got into a heated argument. Suddenly, I heard the nasty edge in his voice. "Don't ever speak to me like that again," I told him in a calm, quiet voice. Only a few days later did I recall the "quills." My brother had thrown a barb at me; this time I didn't let it lodge. The healing had worked, after all.

Since then, investigating healing for my first book, I watched many different healers and also experienced many healing sessions. I even tried healing techniques just to prove they couldn't work-only to find they did work. I also looked at the scientific record.

More than 177 controlled studies of energy healing had been done by 1998 and of those 72.9 percent found significant results. Since then, more studies with findings of significant results have been completed, including at California Pacific Medical Center in San Francisco, where the results of a study of healing and end-stage AIDS patients was so dramatic that the National Institutes of Health is currently funding two large follow-up studies. I now work as a subtle energy healer, using ancient Yogic, Tibetan and Kabbalistic principles, and also teach people to experience their own subtle energy.