**2. Basic concept of traditional Oriental medicine**

Traditional Oriental medicine is based on "Yin" and "Yang" and the "Five Elements Theory" [4, 5]. "Yin" and "Yang" are mutually opposed, representing related aspects of objects and ideas, such as male and female, right and left, and morning and evening. The Five Elements Theory describes five elements: wood, fire, earth, metal, and water, with everything in the world belonging to one of these five elements. For example, the liver, heart, spleen, lungs, and kidneys fall under the elements of wood, fire, earth, metal, and water, respectively. Of note, the liver and heart in Oriental medicine are not the same as the liver and heart as understood in Western medicine; the liver controls the systemic blood flow and Qi. Qi is a transmutable energy in traditional Chinese medicine that is presumed to flow through 12 meridians in the body [6]. Functional damage to the liver subsequently induces headache and vertigo. The heart controls mental activity, such as memory and intelligence, as well as the tongue; therefore, heart dysfunction can cause taste and language dysfunction. The spleen controls the digestion and absorption of food from the stomach, so spleen dysfunction induces stomachache and diarrhea. The lungs control breathing, and the skin is a barrier against external chemicals and infection. Therefore, lung dysfunction results in catching a cold and respiratory dysfunction. The kidneys control vitality and are related to the ears, so kidney dysfunction can cause a number of diseases, chills, and hearing loss.

**Figure 1.** "Creation cycle" and "destruction cycle" (this figure is originally created by authors).

Additionally, the Five Elements Theory includes two relationships: the "creation cycle" and "destruction cycle" (**Figure 1**). The creation cycle is the "mother–child relationship," which repeats in circulation, and the destruction cycle occurs when one of the five elements wins against or limits another element [4]. Oriental medicine applies this theory for medical treatment and diagnosis. By maintaining balanced creation and destruction cycles, we can maintain good health. If those relationships become unbalanced, acupuncture and Chinese medicine are used to restore the balance.
