Common causes of hypothyroidism include: 1. emotional stimulation: mental stimulation leads to liver qi stagnation, liver depression leads to spleen deficiency, then abnormal transportation and transformation, and internal production of damp phlegm. 2. improper diet: improper diet damages the spleen and stomach, insufficient middle qi, abnormal transportation and transformation, diet water and grain cannot be transported and transformed, and phlegm is produced internally; phlegm and dampness are abundant, obstructing qi and damaging spleen yang. The spleen is the basis of the latter. If the spleen is weak, the kidney will be nourished by fire over time, resulting in a deficiency of both the spleen and kidney, the symptoms of loss of appetite, coldness, drowsiness and laziness, and swelling of the whole body will be seen. 3. Invasion of external evil: Mostly wind-heat and poisonous evil invade from the mouth and nose, and the poisonous evil accumulates in the front of the neck, the swelling and pain of the pharynx and the front of the neck will be seen; if cold things are used excessively, internal injury to the yang, although the heat and poison in the neck are removed and the pain disappears, the pronunciation is low, fear of cold, and even swelling. 4.Surgical creation or drug poisoning: Due to thyroidectomy or taking some toxic drugs (such as western drugs for hyperthyroidism), the body’s vital energy is damaged, resulting in the loss of nourishment of the internal organs and the decline of functions, which can show a series of signs of deficiency.