This concept is based on the premise that you alone know yourself best. Through self-hypnosis, you can not only identify the conditions relevant to your health, you can intervene directly in ways that promote healing. Various techniques are employed, but the most common includes a visual (inner) survey of the body itself with the expectation that the sub-conscious mind will seize the opportunity to call attention to areas of the body with need for medical intervention.
Suggested Reading:
Slate & Weschcke: Self-Empowerment Through Self-Hypnosis