By critically evaluating exceptions which may lead to false diagnoses, as well as by improving the currently-used applied kinesiology diagnostic method (="Dysfunction Localization Method"), the author was able to develop the "Thumb-Index Finger Bi-Digital O-Ring Diagnostic Method," using the Applied Kinesiology Dysfunction Localization Principle. By combining the author's "Bi-Digital O-Ring Dysfunction Localization Method" with clinically useful organ representation points in acupuncture medicine (where the presence of tenderness at the organ representation point is used for diagnosis as well as for the location of treatment), it has become possible to make early diagnoses of most of the internal organs, with an average diagnostic accuracy of over 85%, without knowing the patient's history or using any instruments. The method can detect dysfunctioning or diseased organs even before tenderness appears at the organ representation point, with an applied force of less than 1 gm/mm2 on the skin surface, while the detection of tenderness at the organ representation point often requires a minimum applied force of 80-100 gm/mm2. The method was applied to the "Drug and Food Compatibility Test" to determine the probable effects of a given food or drug on individual internal organs without going through time-consuming, expensive laboratory tests. It was also applied to auricular organ representation points and their evaluation, and has succeeded in increasing their diagnostic sensitivity. The method was also used for the evaluation of magnetic fields. Usually the North pole increased muscle strength and the South pole weakened it at most parts of the body. This simple, improved, economical diagnostic method may have invaluable implications in clinical diagnosis, treatment and drug research. Key Words: early diagnostic methods, "Thumb-Index Finger Bi-Digital O-Ring Diagnostic Method," applied kinesiology, cardio-vascular diseases, drugs, tenderness, pain, pain medicine, anti-hypertensive drugs, cardio-vascular drugs, aspirin, Bufferin, gastro-intestinal system, muscle strength, nutrition, magnetic field, sensory nerve, spinal cord, brain stem. Inderal.