Hairy edges of breast nodules are considered to be caused by breast hyperplasia, mastitis and malignant tumor of the breast. 1. Mammary hyperplasia: endocrine disorders caused by the imbalance of estrogen and progesterone ratio, resulting in breast hyperplasia, symptoms manifested as breast nodules or lumps, including granular nodules, striated nodules, etc., the nodules are often multiple, and the edges of the nodules are rough. 2. Mastitis: Inflammation of breast tissue with or without microbial infection, breast swelling and pain, increased body temperature, often accompanied by tenderness and pressure, and the appearance of hard nodules in a certain part of the breast with unclear boundaries, and with the development of the disease, the hardness and pain worsen. 3. Breast malignant tumor: the tumor occurring in the breast, there are benign and malignant tumors, generally benign tumors lumps smooth, slow growth, while malignant tumors grow rapidly, the lumps are hard, often appearing edges shaped like a burr. At the same time, the roughness around the breast nodule may also be caused by tuberculosis, fungal infection and so on. There are many reasons for the rough edges of breast nodules, patients should go to the hospital in a timely manner, complete the relevant examinations, clarify the cause of the disease, and actively treat it to avoid delaying the condition.