Biofeedback is a form of alternative medicine that involves measuring a subject's quantifiable bodily functions such as blood pressure, heart rate, skin temperature, sweat gland activity, and muscle tension, conveying the information to the patient in real-time. This raises the patient's awareness and conscious control of their unconscious physiological activities.

By providing the user access to physiological information about which he or she is generally unaware, biofeedback allows users to gain control of physical processes previously considered an automatic response of the autonomous nervous system. Interest in biofeedback has waxed and waned since its inception in the 1960s; it is, however, undergoing something of a renaissance during the early 21st century, which some experts attribute to the general rise in interest about all alternative medicine modalities. Neurofeedback, a type of biofeedback treatment, has also become a popular treatment for Attention Deficit/Hyperactivity Disorder (ADHD); electromyogram biofeedback, used for muscle tension, has been widely studied and is currently accepted as a treatment for incontinence disorders, and small biofeedback machines are becoming available for a variety of uses in the home. The role of biofeedback in controlling hypertension is also becoming recognised.

The Association for Applied Psychophysiology and Biofeedback, or AAPB is the non-profit scientific and professional society for biofeedback, much akin to the American Psychological Association.

Origin of biofeedback

Neal Miller, a psychologist and neuroscientist who worked and studied at Yale University during the middle of the 20th century, is generally considered the father of modern-day biofeedback. He discovered the basic principles of biofeedback by applying his theory that classical and operant conditioning were both the result of a common learning/conditioning principle. Miller hypothesized that any measurable physiological behavior within the human body would respond in some way to voluntary control. His team found that by stimulating the pleasure center of a paralyzed rat's brain with electricity thereby rewarding them without something that might make them act in some way to make the physiological changes, it was possible to train them to control phenomena ranging from their heart rate to their blood pressure and body temperature. Until Miller's research, it was believed by the scientific community that physiological processes (e.g. heart rate) were solely under the control of the autonomic nervous system and not responsive to conscious effort. Miller later retracted many of his claims because he was unable to replicate much of the data that he had published with Leo DiCara,the primary graduate assistant with whom he published all of his biofeedback results. Leo DiCara, after receiving a tenured position at the University of Michigan because of his groundbreaking work with Miller committed suicide one year later.