Biofeedback is a non-invasive method, which allows one to receive actual feedback from the body and therefore the ability to gain control of involuntary processes. This may include gaining voluntary control over such things as heart rate, muscle tension, blood flow, pain perception and blood pressure. Biofeedback can be used alone or as an adjunct to treat many conditions, including essential hypertension, benign heart arrhythmia, anxiety and stress, chronic pain, migraine and tension headaches.