Biofeedback is a therapy that uses an electrical machine to help you identify, monitor and learn to consciously manage your body's physiological responses. Biofeedback helps people learn to alter activities usually controlled by the autonomic nervous system such as heart rate, blood pressure, and muscle activity. It also can be used to learn relaxation techniques that can reduce stress, headaches and chronic pain. Biofeedback therapy enables people to learn how to consciously manipulate a body function by using feedback gathered by electronic sensors that measure various body functions such as brain waves, temperature, heart rate and muscle tension. The information provided by the electronic instruments enables a person to learn ways to control, reduce or avert certain physical reactions such as those that increase feelings of stress and pain. Certified biofeedback therapists monitor the electronic equipment and train patients in the most effective techniques to control their specific symptoms.