Biofeedback may be used to improve health, performance, and the physiological changes that often occur in conjunction with changes to thoughts, emotions, and behavior. 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. 

Biofeedback is a process of gaining greater awareness of many psychological and physiological functions through the use of instrumentation that mirrors these psychological and physiological processes of which the individual is not normally aware. Electrodes attached to your skin or scalp to measure these processes, which are usually considered involuntary, and display them on a monitor. With help from a therapist, you can learn to change your heart rate, blood pressure, or brainwaves for example. Biofeedback allows the person to receive information about the status of his own biological state, and using this information, learns to gain control over involuntary biological functions. At first you use the monitor to see your progress, but eventually you will be able to achieve success without the monitor or electrodes. 

Some of the processes that can be controlled include brainwaves, blood pressure, muscle tone, skin conductance, heart rate and pain perception. It has been commonly used to treat blood pressure, tension headache, migraine headache, chronic pain, and urinary incontinence. Recent research has now found that a type of biofeedback called neurofeedback is also very effective in the treatment of ADHD.