In traditional Chinese medicine, both hyperthyroidism and hypothyroidism are considered to be a Yin/Yang imbalance. In Chinese philosophical and medical theory, Yin and Yang are the essential components of the material universe. Everything that exists is Yin or Yang (generally a combination of both in a characteristic balance). The Yin principle is dark, moist, receptive, female, sinking, and its electrical charge is negative.
In Chinese terms, when Yin is deficient it cannot control the Yang energy from escaping outward and upward, and this "reckless" movement of Yang brings about the characteristic symptoms of hyperthyroidism. When Yang is deficient, it simply cannot produce the vital energy necessary to keep the body functioning well, and symptoms of hypothyroidism result.
The Yang principle is light, fiery, active, male, outward-expanding, and its electrical charge is positive. A very basic principle of Chinese medicine is to keep the Yin and Yang in balance, since the balance of Yin and Yang represents the healthy state of the body. A treatment intervention by traditional Chinese medicine (which includes acupuncture, herbal medicine, and dietary therapy) is designed to bring the Yin and Yang back to a normal balance. In Western terms, an overproduction or underproduction of thyroid hormone alters the body?s chemical balance and causes hyper- or hypothyroidism.