Acupuncture points have been known for thousands of years, and the principles of electricity have been understood (at least somewhat) since before the 1600s. It has been known for many years that acupuncture points have different electrical conduction than the surrounding tissues. Changes in these electrical readings in conjunction with disease states has been investigated extensively. Meridian stress assessment instruments that measure electrical conduction at acupressure points have been around for over thirty five years. They have been used widely in Europe and virtually around the world for allergy testing as well as for a variety of other purposes. These instruments, however, have been used for only a few years in this country. Meridian stress assessment instruments have been manufactured in Germany, Japan, China, France, Denmark, Russia, and more recently in the United States. Many double-blind studies have been done using this technology. In fact, most of those practitioners who use them have set up a blinded test situation of one kind or another before they really believe that these instruments actually work. Hundreds of patients have been tested in a double-blind fashion where the patient did not know what they were being tested for, and the instrument operator did not know anything about the patient’s reactivity. These tests usually compare favorably to the patient’s history and to testing by other techniques.