Hypothyroidism, or hypothyroidism, does not usually lead directly to mouth ulcers, but hypothyroidism may cause digestive pathology, causing patients to experience loss of appetite. Hypothyroidism is a disorder in which the body’s metabolism is reduced due to a decrease in the synthesis and secretion of thyroid hormones, or a deficiency in their physiologic effects. Patients with hypothyroidism usually suffer from loss of appetite, which affects their eating, and poor eating can lead to inadequate nutritional intake and lack of micronutrients, which can cause mouth ulcers. Mouth ulcers may also be related to genetic factors, trauma, decreased resistance, etc. It is recommended that patients with mouth ulcers go to the hospital in time.