An inverted nipple is usually not a sign of anything harmful. Roughly 10% of women have some degree of nipple inversion, and most cases are congenital, meaning the nipple has been that way since puberty. The key distinction is whether your nipple has always been inverted or whether it recently changed. A nipple that has looked the same for years is almost always benign. A nipple that newly pulls inward, especially on one side, deserves a medical evaluation.
How Common Inverted Nipples Are
Studies estimate that anywhere from 2% to 10% of women have inverted nipples, with the variation largely depending on how strictly researchers define “inverted.” One study of young Korean women found a prevalence of about 3%. Another found that nearly 40% of women in their first pregnancy had at least a minor degree of nipple flatness or failure to protrude normally. The point is that this is an extremely common anatomical variation, not an abnormality.
Inverted nipples can affect one or both sides, and they can be present from birth or develop later in life. Men can have them too, though it’s less commonly discussed.
The Three Grades of Inversion
Nipple inversion is classified on a scale of 1 to 3:
- Grade 1: The nipple can easily be pulled out and stays out on its own. This is the mildest form and often causes no functional problems.
- Grade 2: The nipple can be pulled out but eventually retracts back inward.
- Grade 3: The nipple cannot be pulled out at all. This is the most severe form and can sometimes interfere with breastfeeding.
Grade 1 inversion is by far the most common. Many people with Grade 1 don’t even realize their nipples are technically “inverted” because they pop out with stimulation or cold temperatures.
When It’s Just Normal Anatomy
Congenital nipple inversion happens because the milk ducts connecting to the nipple are slightly shorter than average, pulling the nipple inward. There’s no underlying disease involved. If your nipples have been this way since you developed breasts, there is no medical concern. It’s simply how your body is built, similar to differences in ear shape or belly button depth.
Nipples can also flatten or invert gradually with age. As you approach menopause, milk ducts naturally shorten, and this can pull nipples inward over time. Significant weight loss and the natural sagging of breast tissue can also cause it. These slow, symmetrical changes affecting both sides are generally benign.
When a New Inversion Needs Attention
The scenario that warrants a closer look is a nipple that was previously outward and has recently turned inward. In a study of 414 patients with new nipple inversion, 93.5% turned out to have benign or negative results on imaging. That means the vast majority of even new inversions are not cancer. However, 6.5% did have malignant findings, which is why new inversion should always be checked.
Two patterns raise the level of concern. First, if the inversion is unilateral, meaning only one nipple changes while the other stays the same. Second, if the change happens quickly over weeks or months rather than gradually over years. A rapid, one-sided change has a higher likelihood of an underlying cause that needs investigation.
Possible causes of acquired nipple inversion include:
- Infections: Bacteria can cause abscesses or clogged milk ducts, pulling the nipple inward. Chronic breast tissue infections are particularly common in people who use tobacco products.
- Benign breast disease: Noncancerous lumps or fibrous tissue changes can cause inversion without any cancer being present.
- Breast cancer: When a tumor invades a milk duct, it can pull the nipple flat or inward. This is typically accompanied by other signs like a lump, skin dimpling, or discharge.
- Paget’s disease of the breast: A rare cancer that develops in the nipple skin, sometimes mistaken for eczema because it causes a rash and inflammation alongside nipple changes.
If your nipple has newly inverted, your doctor will likely order imaging (usually a mammogram, ultrasound, or both) to look for any underlying cause. In most cases, the results come back reassuring.
Breastfeeding With Inverted Nipples
One of the most common practical concerns is whether inverted nipples make breastfeeding difficult. For Grade 1 inversion, breastfeeding usually works fine because the baby’s latch can draw the nipple out. Grade 2 and 3 inversion can present more of a challenge, but there are several strategies that help.
Using a breast pump or hand expression just before feeding can draw the nipple outward enough for the baby to latch. Plastic breast shells worn inside the bra between feedings apply gentle traction to gradually coax the nipple out, though the evidence for their effectiveness is mixed. Nipple eversion devices, which use suction to pull the nipple forward, are another option some women find helpful. A lactation consultant can guide you toward the approach that works best for your specific grade of inversion.
Correction Options
If inverted nipples bother you cosmetically or functionally, there are ways to address them. For milder cases, suction-based devices worn regularly over weeks or months can sometimes train the nipple to stay in a more protruded position. These work by gently stretching the shortened ducts that pull the nipple inward.
For Grade 2 or 3 inversion that doesn’t respond to non-surgical methods, a minor surgical procedure can release the tight ducts and tissue holding the nipple in place. The trade-off is that cutting these ducts may affect your ability to breastfeed in the future, so timing matters if you plan to have children. The procedure is typically done under local anesthesia and recovery is relatively quick.
Many people with inverted nipples choose not to pursue any correction at all, and that’s a perfectly reasonable choice. There is no medical need to “fix” a congenital inverted nipple unless it’s causing functional problems or significant distress.