The power of the mind to control bodily functions has been extensively studied in biofeedback research. It has been shown that individuals can learn to control brain wave activity, cardiovascular and respiratory activity, reduce skin temperature and voluntarily modify other autonomic processes. Dr. John Basmajian, MD, professor emeritus at the Department of Medicine, McMaster's University in Canada, has demonstrated that individuals can be taught to gain conscious control over individual neurons and muscle cells. This ability to exercise single cell control through consciousness, suggests the possibility that one can affect any part of the body, given that one knows how this process might work. Several studies have already demonstrated conscious control over tension headaches, high blood pressure, urinary and fecal incontinence, temporal mandibular joint pain, involuntary muscle spasm, muscle paralysis caused by cerebral vascular accident and dyskinesia. According to Elmer Green, PhD, and Alyce Green, founders of the Voluntary Controls Program at the Meninger Clinic in Topeka, Kansas, "This extension of conscious control over voluntary systems has far reaching implications for psychology and medicine. It suggests that human beings are not biological robots controlled entirely by genes and the conditioning of life experiences."

The primary principle of mind-body medicine is that each person is unique. Because no two people are alike, the same disease can have different results in different people. An example of this would be the different ways one might contract pneumonia. One individual may have increased susceptibility due to psychological stress or trauma, another individual may have been run down from overwork or other exhaustion, and yet another person may have nutritional and biochemical imbalances resulting in susceptibility.

The next tenant of mind-body medicine is chronic stress. Within mind-body medicine it is felt that chronic stress and lack of balance contribute to illness. It is felt that relaxation, positive methods of coping with stress and a restoration of total life balance, lead to a restoration of health. Dr. Peter Nixon, a British cardiologist, points out that a chronic, increased state of stress results in numerous changes of body function. These eventually interfere with immune system function, protein synthesis and cardiac function. Repetitive stress also uses up the body's reserves, leading to increased stress on the psychological function.