Nipple

The small prominence at the tip of each breast. Women’s nipples contain tiny openings through which milk can pass. The nipple and the areola, a surrounding area of dark skin, both increase in size during pregnancy. Involuntary muscle in the nipple allows it to become erect. Structural defects of the nipple are rare. An inverted nipple is usually a harmless abnormality of development. Nipple inversion that develops in older women is mostly due to ageing, but mammography may be advisable to rule out the possibility of cancer. Cracked nipples, common in the last months of pregnancy and during breastfeeding, may lead to infective mastitis. Washing, drying, and moisturizing the nipple daily can help to prevent cracking. Papilloma of the nipple is a noncancerous swelling attached to the skin by a stalk. Paget’s disease of the nipple appears initially as persistent eczema of the nipple and is due to a slow-growing cancer arising in a milk duct. Surgical treatment is required. Discharge from the nipple occurs for various reasons. A clear, straw-coloured discharge may develop in early pregnancy; a milky discharge may occur after breast-feeding is over. Galactorrhoea (milk discharge in someone who is not pregnant or breast-feeding) may be caused by a hormone imbalance, or, rarely, a galactocele (a cyst under the areola). A discharge containing pus indicates a breast abscess. A bloodstained discharge may be due to a noncancerous breast disorder or cancer.