If you’ve ever wished bras came in mix-and-match cup sizes, you’re in good company. In one small study, 44% of women said one breast is smaller than the other. And that’s just volume. When you take nipple size and breast shape into account, a whopping 88% of women report a difference up top.

It’s true: Some people have more than two nipples. About 1% of women get them, and twice as many men. But they’re often smaller than other nipples. They show up at birth, usually along the body’s “milk line” -- somewhere between shoulders and legs. It’s rare, but they can form on other parts of the body, including the forehead and foot.

It’s normal to have a few small hairs on the areolae, or the dark skin around your nipple. If it bothers you, clip it with small scissors. It’s best not to pluck or shave, which can cause ingrown hairs and infection.

“Nipplegasms” are real. Nipples are full of nerves, and MRI tests show that fondling them “lights up” the same part of the brain that’s linked to your genitals. This means that for some women, getting to second base is as much fun as going to home plate.

Organs have a purpose. The breast’s job is to make milk. That happens in small lobules inside the breast,. A series of ducts carry it out through the nipple. Fun fact: Men don’t have these lobules, since they don’t breastfeed.

The average breast weighs between 5.3 and 7 ounces. One that’s full of your baby’s meals can weigh as much as 17 ounces. No wonder your back hurts.

Nursing isn't the problem. Sagging is about getting older. Age loosens firmness and elasticity. Smoking, more than one pregnancy, and changes in your weight can also make your "girls" head south.

Discharge during late pregnancy, after giving birth, and if you’re breastfeeding is fine. Any other time, it’s not. A leak can signal a number of things, from thyroid and other hormone problems to cancer, so see your doctor to get it checked out.

Up to 85% of women wear bras that don’t fit. That’s not good, because a lack of proper support can lead to poor posture, neck and back pain, and even nerve problems in your arms and shoulders.

Your size changes -- a lot. Your weight, pregnancy, and menopause affect the size and type of bra you need. Get measured to find the right fit. A pro at a department or lingerie store is your best bet, but a trusty measuring tape works, too.

The grass is greener on the other bustline. Fewer than a third of women ages 18 to 65 say they like the size and shape of their breasts. Some women want smaller breasts and go for breast reduction surgery. For others, bigger is better, and they turn to breast augmentation. Short of plastic surgery, a better bra and a kinder body image could be the boon to feel better about your boobs.