There are many reasons for nipple enlargement, as follows: 1, nipple injury, nipple is impacted, squeezed nipple congestion and swelling pain, you can first use an ice pack cold compress, and then hot towels hot compresses, you can spray Yunnan Baiyao aerosol to activate blood circulation. 2, nipple allergy, nipple contact with low-quality bras or creams lead to nipple allergies, nipple itching, pain, swelling. You need to replace good quality bras and creams and take antihistamine medication at the same time. 3, puberty development, breast and nipple development during puberty, nipple enlargement is normal, nipple will be stereotyped after puberty. 4, mammary fibroids, is a benign disease, in pregnancy and lactation, the tumor in the breast will be rapidly increasing phenomenon, the nipple will also appear to be relatively large accordingly. After the discovery and diagnosis, it is necessary to actively remove the fibroid tumor and the peritoneum.