There are eight different types of nipple in the world, a pediatrician and dermatologist has declared - though you might find it trickier than you think to decide which one is yours.
While most people will find it easy to recognise which category they fall into, some may find themselves identifying with more than one, or even a combination ranging from puffy to flat, inverted to protruding.
And the reassuring thing is that no matter which one is more true to type for you personally, they're all perfectly normal.
Dr Tsippora Shainhouse, a clinical instructor at the University of California, gave magazine Seventeen a run-down of the most commonly-found varieties. These are:
Nipples that are raised a few millimetres above the surface of the skin. They usually point downwards and can become harder when stimulated or cold.
The whole nipple lies flat against the skin and blends into the surrounding areola - yet will still become erect when stimulated or cold.
The entire nipple area is raised and lies on top of the breast. The nipple can become more pronounced with cold or stimulation.
Depending on how severely inverted the nipple is, it can be teased outwards using your fingers - unless the muscles are too tight. It usually lies inwards.
Just one nipple protrudes - the other lies inwards, or retracts. If this has always been the case, there's no reason to worry. But if this suddenly starts happening when it didn't before, then see a doctor immediately - it could be a sign of breast cancer.
Most people have small glands surrounding their areola, known as Montgomery glands, but some are bumpier than others. They resemble whitehead spots and you maybe even be able to squeeze dead skin cells out of them - but don't play around with them too much.
Some women are hairier than others, but it's very normal for women to have dark hairs growing out of their areola. Some hairs may be fine, others coarse - either way, it's perfectly safe to tweeze them out if they bother you.
Some people have small, extra nipples beneath their breasts or on other parts of their torso that closely resemble a flat mole or small, raised bump.