Biofeedback is a technique in which you learn to control certain biological responses, in order to manage pain or health problems. It relies on the power of the mind to cause various physical changes in your body. Typically, biofeedback is used in conjunction with standard pain medicine or therapies. While it might not work for everyone, biofeedback has the advantage of being painless and free of side effects. The technique may be used for conditions such as headaches; muscle pain and stiffness; asthma (AZ-muh); irregular heart rate; and high blood pressure. Once your ailment is diagnosed, you'll be given a particular task to concentrate on. For example, a therapist may ask you to control functions like heart rate, temperature, or blood flow. A desired goal is set, and you're connected to a polygraph device which measures your physiological (fizz-ee-oh-LAW-jih-kul) responses. When you achieve the goal response, the machine may beep or flash a light. Other machines may present readings in actual numbers. Generally, you start out with an easy goal, and work towards more and more challenging goals. Ultimately, the object is to regulate certain body functions at will, without relying on readings from a machine. To learn more about biofeedback, consult a health care provider.