The thyroid and breast are not necessarily related, but both diseases are caused by endocrine abnormalities in the patient’s body. The thyroid gland is a butterfly-shaped gland located in the middle and low parts of the head and neck, and its main function is to produce thyroxine, a hormone that affects cells throughout the body and helps control metabolism, heart rate and basal body temperature. Mammary gland hyperplasia is caused by endocrine disorders, resulting in lumps in the breast, pain, personality changes, menstrual irregularities and other symptoms, and is also affected by the physiological cycle, with symptoms more pronounced before the onset of menstruation and relieved after it. In summary, the two are not substantially related and should be treated separately.