Why does anyone have three nipples? & bull; hello healthy

Guess what, what do Mark Wahlberg, Tilda Swinton, Lily Allen, and One Direction's Harry Styles have in common? You are equally famous, huh. But, there is something else these four celebs have in common that many people may not know - they all share extra nipples. Three nipples, to be precise.

About one in 50 women and 1 in 100 men have three nipples, although some humans have recorded as many as six additional nipples.

Is the third nipple a disease or birth defect?

Third (or fourth, fifth,…) nipples have many aliases, ranging from supernumerary nipples, accessory nipples, pseudomamma, polythelia, or polymastia. This additional nipple will often not develop as a fully functional nipple. Third nipples usually have no medical impact as long as there are no other faulty aspects of your body.

All mammals can have additional nipples. Nipple development is divided into eight stages. The first stage is the nipple which forms like a mole. The final stage is the normal functioning of the female breast or male chest. The terms "supernumerary" and "accessories" mean additions. Pseudomamma refers to fake or unnecessary breast tissue in general. Meanwhile, polymastia refers to the additional features of the nipple which are accompanied by the mammary glands. Polythelia refers to the addition of the nipple only, without the areola - and this is the most common form.

Reporting from The Register, the third nipple can sometimes be considered a mole or simply a birthmark. It is generally one centimeter in diameter and appears along the vertical milk line starting at the armpit and moving down the chest to the groin, in both men and women, although not always. A 2006 medical report found a woman who had a third nipple growing on the sole of her foot, complete with areola and fine hairs.

What causes three nipples in humans?

In order to understand how the extra nipple appears, you first need to understand how the nipple actually originates. After the serma fertilizes the egg, an embryo will be formed. Around the fourth week of embryonic development, the two strips of ectoderm (the part that eventually becomes skin) will be slightly thickened. These two stripes will form a vertical milk line. In the weeks and months after that, these strips will progressively thicken and develop into mammary glands. Eventually, these mammary glands will constrict except for the chest area, where the chest - or breasts - and nipples will continue to grow and develop.

However, sometimes these mammary glands do not disappear completely. When this occurs, an additional nipple is formed, either as an additional breast complete with an areola, or just the nipple.

The extra nipple can also secrete milk

In general, these additional nipples will not develop into full, normal breasts at puberty. However, if glandular tissue is found - the same type of tissue as a normal nipple - then this additional nipple can undergo the same hormonal changes and the same diseases that affect normal breast tissue, such as breast cancer. In addition, additional nipples can also change their pigmentation, swell, soften, or even secrete milk. In this case, the additional nipple will function like a normal breast and nipple, except that it is found in another location of the body.

If the additional nipple is found above another normal nipple position, this condition will make it difficult for women after childbirth when lactation occurs simultaneously with both normal nipples, said Norman A. Grossl in the Southern Medical Journal, quoted by BBC Future.

Relationship of additional nipples to bladder abnormalities

Although breast and additional nipples are not uncommon, several studies have shown an association between additional nipples and malformations of the bladder or kidney tract, although it is not known what causes this association. Researchers suspect that this association arises because the bladder, kidney, and mammary gland systems develop at the same time during embryonic development, but further research is needed to confirm this conjecture.

So far, the triple nipple phenomenon is only one in a million bodily anomalies that may arise in the human body as a result of genetic variation. Additional nipples do not require any special therapy or treatment, however, in certain cases, some people choose to undergo a surgical procedure to remove their additional nipples, for cosmetic reasons and purely appearance considerations.