Breast moles may be caused by vascular nevus, purpura, spider nevus and so on. 1. Vascular nevus: this disease may be related to sun exposure, hormone metabolism, physical factors, age factors, etc., but also skin aging, is a relatively common benign skin tumors, the patient is mainly manifested as a round red papule of the size of a needle tip to a grain of rice, and fading will occur when pressed. 2. Purpura: this disease is mainly due to allergic factors caused by vascular inflammatory reaction, so that patients appear breast mole situation, resulting in subcutaneous capillary rupture, skin red spots and ecchymosis and other symptoms, accompanied by pain, itching. 3. Spider nevus: breast mole may be caused by spider nevus, mostly due to liver diseases, such as cirrhosis, viral hepatitis, but also with estrogen level increase. At the same time, the breast may also exist pigmented nevus, belonging to the benign tumor of melanocytes, located in the superficial part of the dermis, whose substance is nevus cells, and whose interstitium is blood vessels, lymphatic vessels and connective tissues. It is recommended not to stimulate and rub it frequently to prevent cancerous changes. If the nevus suddenly grows, becomes black, ulcerated, satellite foci appear, etc., it is the precursor of malignant transformation. Timely treatment is needed. It is suggested that patients should go to regular hospitals in time, and under the diagnosis of doctors, according to the condition of patients, carry out targeted treatment.