1.Endocrine disorders: Some studies suggest that there is a relationship between the imbalance of hypothalamic-pituitary-thyroid axis system and the occurrence of thyroid adenoma. Animal experiments show that when the blood level of thyroid stimulating hormone is at a high level in rats, the incidence of thyroid adenoma will increase, while the incidence can be reduced after the addition of thyroid tablets. Estrogen may also be one of the carcinogenic factors. 2.Some thyroid proliferative diseases: such as adenomatous goiter, hyperfunctioning goiter, thyroid adenoma growing for many years, can become cancerous. 3.Hereditary factors: It may be related to genetic factors. The prevalence of the disease is also higher among family members of patients with thyroid adenoma. Human leukocyte antigen is a marker of heredity. A number of studies have found that one or more human leukocyte antigens are significantly increased in patients with toxic diffuse goiter, further indicating that the disease is closely related to heredity. 4, radiation damage: external radiation exposure to the head and neck during infancy is an important factor in the development of thyroid adenoma, the younger the irradiated child, the higher the risk of cancer, and women are generally higher than men. If the patient does not receive timely treatment, the tumor will gradually grow, and individual patients with particularly large tumors will have their trachea, esophagus or laryngeal nerve compressed by the tumor, resulting in symptoms such as difficulty in breathing and swallowing. In the long run, cancer may occur. Therefore, patients should pay attention to it. Early treatment is the key.