Why Some People Have a Third Nipple

A third nipple is an extra nipple on the chest. Also called a supernumerary nipple, it's usually smaller than a regular nipple and often mistaken for a mole or birthmark. Third nipples are common, typically harmless, and usually don't need to be removed for health reasons.

Some third nipples are accompanied by breast tissue, while others are not. Those that are should be monitored for breast cancer.

In this article, you'll learn about extra nipples, why they develop, and their potential complications.

How Do You Tell If It's a Third Nipple?

Extra nipples form before birth, after the breasts and mammary glands. Extra nipples can appear in people of any sex and are more common in those assigned male at birth (AMAB).

While people AMAB don't generally develop female breast tissue, which happens in response to female puberty hormones, they do have mammary glands.

Third nipples don't all look the same. Some have a typical nipple appearance—and even an areola or breast tissue. Others are just small bumps and some may be mistaken for moles.

Features like the location, size, color, and texture can help you figure out whether it's a third nipple or something else.

Location

While third nipples can be anywhere on your chest, they most often form before birth and along milk lines.

Milk lines are ridges that arch down from the armpit to the groin on both sides of the body, along the same paths where some mammals have multiple pairs of nipples. They appear around the sixth week of fetal development and disintegrate by about week nine.

Occasionally, however, milk lines stick around for longer and cause extra nipples and even breast tissue to form.

Size

Regular nipples vary greatly in size, and so do extra ones. Most of the time, a supernumerary nipple is smaller than your other nipples.

If the third nipple is associated with an areola, that's generally smaller, too.

In some cases, third nipples are no bigger than a freckle.

Texture

Third nipples have a bumpy texture like standard nipples. Some moles feel rough but usually aren't as rough as a nipple.

Extra nipples are also raised above the skin instead of flat. They may also have a visible dimple.

Color

Supernumerary nipples are pigmented. Most often, they're the same color as your other nipples, so pink or brown.

Nipples can change color over the course of your life time due to hormonal fluctuations. This may happen to third nipples, as well.

Types of Third Nipples

Third nipples fall into one of six main categories determined by what "extras" you have. It's possible to have more than one supernumerary nipple, which can be different types.

When an extra nipple occurs alone (category 6), the condition is referred to as polythelia. When the third nipple is connected to breast tissue and glands (categories 1 and 2), it's called polymastia.

Health Concerns Related to Third Nipples

While a third nipple itself is no cause for concern, it may be associated with increased risks of some health problems.

Breast Cancer and Third Nipples

If you have polymastia, that extra breast tissue is vulnerable to the same diseases that can affect typical breast tissue. Third nipples should be examined for breast cancer just as your regular breasts are.

Breast cancer risk is tied to a genetic mutation called BRCA2. A possible link between this mutation and supernumerary nipples was suggested in a 2017 study on a brother and sister. Both siblings had:

• Breast cancer
• BRCA2 mutations
• Two supernumerary nipples

The exact association between these things isn't yet known. However, if you have a third nipple, you may want to ask your healthcare provider about genetic testing for BRCA2 mutations.

Paget's Disease of the Nipple

In rare cases, category 5 and 6 extra nipples (not attached to breast tissue) may be affected by a cancer of the nipples known as Paget's disease of the nipple.

Talk to your healthcare provider about Paget's disease if you have third-nipple symptoms such as:

• Itching
• Burning
• Pain
• Flattening
• Yellow or bloody discharge
• A lump

Paget's can sometimes also show up in the groin area (at the lower end of the milk lines), where it is called extramammary Paget's disease (EMPD).

Other Health Risks

You may face other potential health problems if you have a third nipple. Supernumerary nipples have been associated with:

• Kidney and urinary tract malformations
• Heart arrhythmias (irregular rhythm)
• Hypertension (high blood pressure)
• Peptic ulcer disease
• Migraine
• Testicular cancer

Polythelia (category six) is also associated with a higher risk of genital, bladder, and kidney cancers.

When to See Your Healthcare Provider

In most people, extra nipples are benign. Still, you should talk to your healthcare provider if you note any changes such as dryness or flakiness, a rash, pain, or a lump.

Not all nipple changes indicate breast cancer, but knowing which changes are normal and which are signs of disease is important to your health.

Be sure your healthcare provider knows about your third nipple, especially if it's attached to breast tissue. It should be looked at during breast exams. It could also make a difference in whether they think genetic testing for familial breast cancers is important for you.

Third Nipple Removal

Third nipples don't usually need to be removed, but some people get them taken off for cosmetic reasons or if they cause discomfort. Surgical procedures vary depending on whether it has or underlying breast tissue.

Isolated third nipples can be removed via a simple procedure, similar to the removal of a mole. If it's connected to breast tissue, a mastectomy (surgical removal) can be done.

Summary

Third nipples are a fairly common occurrence. Most often, they're not associated with any underlying problems.

While they don't increase your risk of breast cancer, they may be at risk for any disease that typical breasts may develop. Third nipples are also associated with various medical conditions and other types of cancer, so it is important to go for regular check-ups.

You can have extra nipples (and associated breast tissue) removed for medical or cosmetic reasons.