Mild breast hyperplasia may generally be caused by endocrine disorders, increased estrogen levels, excessive hyperplasia, etc. You should go to the hospital as soon as possible and under the guidance of the doctor for treatment. 1. Endocrine disorders: the endocrine system cooperates with various biochemical enzymes to maintain the relative stability of the environment in the human body. Usually, environmental and physiological factors may cause endocrine disorders, which may lead to mild breast hyperplasia. 2. Increased estrogen level: Estrogen is an important sex hormone to maintain female secondary sex characteristics. With increased estrogen level, patients usually have abnormal hypothalamus pituitary function, which promotes the secretion of gonadotropins, prompting the secretion of estrogen from the ovaries, leading to mild breast hyperplasia. 3. Excessive hyperplasia: excessive hyperplasia is usually caused by excessive proliferation of connective tissues in the process of repairing and healing after trauma, forming localized elevated lumps, which results in mild breast hyperplasia. Mild breast hyperplasia may also be related to the patient’s poor diet and mental factors, etc. Patients should go to the hospital in time, under the guidance of the doctor for treatment.