Everything you want to know about breasts — and then some

We consulted Dr. Brett Beber, a plastic surgeon at Toronto's Women's College Hospital, as well as a stack of medical textbooks and studies, for the answers to your questions about your breasts.

What are these things, actually? Here is the scientific (and outrageously unsexy) answer: The breast is essentially a modified sweat gland made up of fatty, glandular and fibrous tissue.

When do breasts stop growing — if ever? Your breasts usually stop developing when you’re 18 or 19, but thanks to pregnancy, menopause and weight gain or loss, they’ll continue to change throughout your lifetime.

Are they meant to be the same size? Your breasts are not supposed to be mirror images of each other — think of them as sisters, not twins.

Are they meant to hurt a whole bunch? Many women experience breast tenderness right before their period, when progesterone spikes and milk ducts swell. But if the pain is new or affecting your life, give your doctor a shout.

This lump in my breast is probably nothing, right? A reassuring stat: It’s estimated that between 80 and 85 percent of lumps are benign fibroids or cysts. But, again, let your doc know.

French researchers claim that wearing a bra contributes to sagging. Vrai ou faux? The idea that you can prevent breast sagging by dispensing with your underwire and exercising your chest muscles (i.e. free-boobing) is a myth. Blame gravity, not your bra — and you can also blame genes. Some breasts drop more than others.

What else do women get wrong about bras? We have no idea which ones to wear. According to a survey from lingerie company Triumph International, more than three-quarters of women are in the wrong bra size. We generally tend to overestimate band size and underestimate cup size.

My bra straps dig into my shoulders. How bad can that be? Bad enough to cause numbness in your little finger.

Did I inherit my breasts from my mom? The genetics of breast size is not completely understood, but it seems that some women take after their mothers, while others take after the women on their father’s side.

Am I flat because I slept on my chest as a child? No.

Okay, but since I’m flat, I don’t need a sports bra, right? When you’re out jogging, your small breasts can still bounce up and down by more than three inches. So maybe strap them in.

What’s with the hair on my nipples? Can I pluck it? Hey, humans are mammals and mammals have hair, including around the nipple area. Plucking, waxing and laser hair removal are just as safe on your nipples as anywhere else on your body — provided they’re done properly.

How come my nipples are itchy? Eczema can happen during breastfeeding, pregnancy or just due to the changing of the seasons. If the skin on your nipple seems dry or damaged, try lanolin cream or extra-virgin coconut oil.

What’s going on with my nipples during sex? When you’re turned on, your nipples expand, widening a little and lengthening by up to 1 cm. After you have an orgasm, your nipples will deflate again.

I don’t really like having my nipples touched in bed. Is that strange? Not according to famed sex researcher Alfred Kinsey, who estimated that half of women did not experience erotic sensitivity in their nipples and breasts.

I have inverted nipples. Am I alone? Nope. If you were to round up 100 nipples, most of them will be outies, but 10 to 20 will be innies.

More: Boob diaries: 6 women share their breast hang-ups and joys What I’d tell my teenage self about breasts 14 bras for the pragmatist or the provocateur