Inflammation and suppuration of nipple refers to the inflammation and suppuration of nipple after infection caused by bacteria invasion when the nipple is not sterilized properly due to deformity, trauma and skin breakage caused by breastfeeding and sucking of babies. 1. Nipple deformity: common in congenital developmental abnormality of the nipple, most commonly seen in the clinical nipple inversion, nipple inversion is often the accumulation of secretion, which is conducive to the growth and reproduction of bacteria, and then cause inflammation and pus in the nipple. 2. Skin breakage: it is mostly seen in skin breakage caused by nipple trauma or mechanical stimulation, etc. If disinfection treatment is not timely, it can lead to the invasion of bacteria from the broken place, and then lead to nipple inflammation. 3. Infant sucking: Mostly seen in breastfeeding first-time mothers, when the baby sucking nipple caused nipple skin breakage or nipple cracks, bacteria invasion caused nipple inflammation, the presence of milk stagnation can also lead to mastitis. When the nipple is inflamed with pus, it is recommended to consult a doctor in time for treatment by a specialized physician.