|Classification and external resources|
Breast with an inverted nipple.
An inverted nipple (occasionally invaginated nipple) is a condition where the nipple, instead of pointing outward, is retracted into the breast. In some cases, the nipple will be temporarily protruded if stimulated, but in others, the inversion remains regardless of stimulus. Women and men can have inverted nipples.
Pregnancy and breastfeeding 
Individuals with inverted nipples may find that their nipples protract (come out) temporarily or permanently during pregnancy, or as a result of breastfeeding. Most women with inverted nipples who give birth are able to breastfeed without complication, but inexperienced mothers may experience higher than average pain and soreness when initially attempting to breastfeed. When a mother uses proper breastfeeding technique, the infant latches onto the areola, not the nipple, so women with inverted nipples are actually able to breastfeed without issue. An infant that latches on well may be able to slush out an inverted nipple. The use of a breast pump or other suction device immediately before a feeding may help to draw out inverted nipples. A hospital grade electric pump may be used for this purpose. Some women also find that using a nipple shield can help facilitate breastfeeding. Frequent stimulation such as sexual intercourse and foreplay (such as nipple sucking) also helps the nipple protract.
Plastic surgery is one method of protracting inverted nipples. If a woman elects to have this surgery performed on her inverted nipples, it can permanently destroy her capacity to breastfeed. Another method of protracting inverted nipples is to have the nipple pierced. This method will only be effective if the nipple can be temporarily protracted. If pierced when protracted, the jewelry may prevent the nipple from returning to its inverted state. The success of both of these methods, from a cosmetic standpoint, is mixed.
Other strategies for protracting inverted nipples include regularly stimulating the nipples to a protruding state, in an attempt to gradually loosen the nipple tissue. Some sex toys designed for nipple stimulation, such as suction cups or clamps may also cause inverted nipples to protract or stay protracted longer. There are special devices specifically designed to draw out inverted nipples or a homemade nipple protractor can be constructed out of a 10 cc disposable syringe. These methods are often used in preparation for breast-feeding, which can sometimes cause inverted nipples to become protracted permanently.
Two methods which are now discouraged are breast shells and the Hoffman technique. Breast shells may be used to apply gentle constant pressure to the areola to try to break any adhesions under the skin that are preventing the nipple from being drawn out. The shells are worn inside the bra. The Hoffman technique is a nipple stretching exercise that may help loosen the adhesions at the base of the nipple when performed several times a day. Although both techniques are heavily promoted, a 1992 study found that not only do shells and the Hoffman technique not promote more successful breastfeeding, but they may also actually disrupt it.
The most common causes of nipple inversion include:
- Born with condition
- Trauma which can be caused by conditions such as fat necrosis, scars or it may be a result of surgery
- Breast Sagging, Drooping or Ptosis
- Breast cancer including breast carcinoma, Paget's disease and Inflammatory Breast Cancer (IBC)
- Breast infections or inflammations such as mammary duct ectasia, breast abscess or mastitis
- Genetic variant of nipple shape such as Weaver syndrome, Fryns-Aftimos syndrome, Chromosome 2q Deletion or congenital disorder of glycosylation type 1A & 1 L or Kennerknecht-Sorgo-Oberhoffer syndrome
- Holoprosencephaly, recurrent infections, and monocytosis
Inverted nipples can also occur after sudden and major weight loss.
Grading system 
Inverted nipple Grade 1 refers to nipples that can easily be pulled out, by using finger pressure around the aureola. The Grade 1 inverted nipple maintains its projections and rarely retracts. Also, Grade 1 inverted nipples may occasionally pop up without manipulation or pressure. Milk ducts are usually not compromised and breast feeding is possible. These are "shy nipples". It is believed to have minimal or no fibrosis. There is no soft-tissue deficiency of the nipple. The lactiferous duct should be normal without any retraction.
Inverted nipple Grade 2 is the nipple which can be pulled out, though not as easily as the grade 1 inverted nipple but which retracts after pressure is released. Breast feeding could be possible even though it is more likely to be either very difficult or impossible. Grade 2 nipples have a moderate degree of fibrosis. The lactiferous ducts are mildly retracted but do not need to be cut for the release of fibrosis. On histological examination, these nipples have rich collagenous stromata with numerous bundles of smooth muscle. Most women with this problem suffer from inverted nipples Grade 2.
Inverted nipple Grade 3 describes a severely inverted and retracted nipple which can rarely be pulled out physically and which requires surgery in order to be protracted. Milk ducts are often constricted and breast feeding is impossible. Women with Grade 3 inverted nipples may also struggle with infections, rashes, or problems with nipple hygiene. The fibrosis is remarkable and lactiferous ducts are short and severely retracted. The bulk of soft tissue is markedly insufficient in the nipple. Histologically, there are atrophic terminal duct lobular units and severe fibrosis.
Modification options 
Correction of inverted nipples may be done in several ways depending on the degree of retraction. However, recovery is specific to each procedure.
Although surgery is normally performed as outpatient procedures and patients are able to go home after few hours following the surgery, some women may be asked to remain in the hospital overnight. However, the patients are advised to avoid driving immediately after the procedure because they will be still under the effect of anesthesia; therefore it is best to be driven home by a friend or relative. The main side effects of surgery are pain, swelling and sensitivity in the nipple area which can last for up to two weeks after the procedure has been performed.
Recovery time is however different with each patient. Patients are encouraged to move around immediately after surgery and after they get home they are recommended to stay in bed for 2 days following the procedure. Patients can generally go back to work in a week after the surgery.
Immediately after the procedure the nipples will more likely feel sore. The soreness should diminish however within few days. Most of the time, patients are prescribed pain killers to help them cope with the discomfort.
Medicated gauze is used following the surgical procedure to cover the nipples. They have the aim to protect the small stitched incisions on the nipple. Patients may feel a little groggy as a side effect of the surgery, but this feeling is expected to subside within a day or so. Patients are recommended not to shower the same day when the surgery was performed, but the next day.
Patients normally experience mild to moderate swelling which peaks two or three days after the procedure, and then disappears rapidly over the following three weeks. Bruising is rare. The sutures are removed four days after the procedure.
Risks that are carried by this type of surgery include infection, unsatisfactory results, excessive bleeding, adverse reaction to anesthesia, and the need for second or sometimes third procedures. The ability to breastfeed cannot be guaranteed after any surgery to correct inverted nipples. Therefore, the patient should clearly specify if she takes into consideration having babies in the future and breastfeeding them.
- Alexander, JM; et al. (April 1992). "Randomized controlled trial of breast shells and Hoffman's exercises for inverted and non-proctractile nipples,". British Medical Journal. 304 (6833): 1030–2. doi:10.1136/bmj.304.6833.1030. PMC 1881748. PMID 1586788.
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- "Types of Inverted Nipples". Retrieved 2010-04-05.
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