Biofeedback devices measure factors such as heart rate, skin temperature, perspiration, breathing rate, muscle tension and brain activity, and "feed back" information about changes in these using visual or sound signals. The instruments -- which can be a simple thermometer or computerized equipment - don't themselves affect your condition, but give you information about your body's state both when the problem is present and when it is not. Using biofeedback, you learn to monitor your body and to use methods such as guided imagery or progressive muscle relaxation to change its responses. The technique is taught in a series of sessions over a number of weeks. Patients eventually learn to monitor and control their conditions without using the devices.
Biofeedback is used in a variety of conditions, including headaches, chronic pain, ulcers, addictions, asthma, high blood pressure, epilepsy, irritable bowel syndrome, incontinence and sleep problems.