Biofeedback is a technique that trains people to improve their health by controlling certain bodily processes that normally happen involuntarily, such as heart rate, blood pressure, muscle tension, and skin temperature. Electrodes attached to your skin -- or in some cases, sensors held in your hands -- measure these processes and display them on a monitor. With help from a biofeedback therapist, you can learn to change your heart rate or blood pressure, for example. At first you use the monitor to see your progress. But eventually you will be able to achieve success without a monitor or electrodes. Biofeedback is an effective therapy for many conditions, although it is primarily used to treat high blood pressure, tension headache, migraine headache, chronic pain, and urinary incontinence. Psychologists use it to help tense and anxious clients learn to relax. Specialists in many different fields use biofeedback to help their patients cope with pain.