Simply put, biofeedback is a method of gaining conscious control of normally unconscious physiologic processes. As a method of treatment, the purpose is to retrain healthier mental and physical habits.

An example of this is a deep breathing exercise, usually recommended for nervous or anxious people. The simple act of paying attention to one's own breathing, then deliberately and repeatedly breathing more slowly and deeply, is an effective way to calm down for many. It is one of the simplest forms of biofeedback.

Among the more elaborate forms are EEG and HEG biofeedback, both of which are also known as neurofeedback, or neurotherapy.

Anxiety is only one of many problems that may benefit from biofeedback. Others include problems with attention (ADHD), depression, obsessive-compulsive disorder, drug addiction (including alcohol), and migraines.