Health professionals have explained what inverted nipples are, and when they might actually be a cause for concern.
An inverted nipple is one that points inwards instead of outwards, as the name would suggest.
However, they are slightly more common than you may imagine, as 10-20% of women are born with them.
Advert
They usually appear on both sides from birth, but can sometimes appear gradually as a person gets slightly older.
And while they are usually no cause for concern, there are some instances when inverted nipples could mean something more serious is underlying.
Health experts warn that if they nipples suddenly start to invert - over weeks or months - then it could be time to contact your GP.
Saranya Chumsri, a hematologist-oncologist at the Mayo Clinic in Florida, said: "These patients should go in to see a provider right away."
Advert
This is because inverted nipples can be a sign of breast cancer, in both men and women.
When the symptom is caused by cancer, it is usually because there is a tumour causing the structure of the breast to change.
The expert added: "When the mass is getting bigger in the nipple area, it can cause a kind of fibrous band and pull in the nipple."
Advert
It can happen in both the early and the later stages of cancer, depending on how close to the surface the tumour starts to grow.
Paget’s disease makes up about 1-4% of breast cancers, and can also cause the nipple to invert.
It develops in the nipple or the surrounding areola, and causes symptoms such as crusty, red skin on the nipple or areola, burning or itching, and bloody or yellow nipple discharge.
However, there are other reasons why nipples may become inverted out of nowhere, that are non-cancerous.
Advert
These include an infection in your milk duct, injury, for example scarred milk ducts from breastfeeding, shortening and widening of milk ducts as a person approaches menopause, breast sagging that occurs naturally with age, and sudden weight loss.
There is a grading system that determines how inverted the nipples actually are.
Grade one are known as 'shy nipples' - they can be pulled out using fingers and will stay pointed outward for a few minutes before going back in.
Advert
Grade two are nipples that can be pulled out but retrieve straight back inwards.
Grade three inverted nipples cannot be pulled out at all.
And whilst breastfeeding is still possible with those for grade one and two nipples, somebody with a grade three case would struggle, according to experts.
Topics: Health, Women's Health, Advice, NHS