What is Bio-feedback?

A method of monitoring minute metabolic changes in one's own body with the aid of sensitive machines. The technique is used especially for stress-related conditions such as asthma, migraines, insomnia, and high blood pressure. The patients are made to learn to make subtle adjustments to move toward a more balanced internal state by consciously visualizing, relaxing, or imagining while observing light, sound, or metered feedback.

Further reading on Bio-feedback:

Biofeedback is a form of alternative medicine that involves measuring a subject's bodily processes such as blood pressure, heart rate, skin temperature, galvanic skin response (sweating), and muscle tension and conveying such information to him or her in real-time in order to raise his or her awareness and conscious control of the related physiological activities.

By providing access to physiological information about which the user is generally unaware, biofeedback allows users to gain control over physical processes previously considered automatic. Interest in biofeedback has waxed and waned since its inception in the 1960s; at the beginning of the 21st century it is undergoing something of a renaissance, which some ascribe to the general upswing of interest in alternative medicine modalities. Neurofeedback has become a popular treatment for ADHD; electromyogram (muscle tension) biofeedback has been widely studied and accepted as a treatment for incontinence disorders, and small home biofeedback machines are becoming available for a variety of uses. Its role in controlling hypertension is becoming recognised