Jenny Chang / BuzzFeed 1. Most people have lumpy, bumpy boobs. 5ph / Getty Images / Via thinkstockphotos.com The fancy medical term for this is fibrocystic breast changes, and it refers to breast tissue that's particularly lumpy, with little fluid-filled cysts. It used to be called fibrocystic breast disease, but it's actually something that affects more than half of women at some point, so doctors dropped the word "disease," Dr. Sandhya Pruthi, an internist specializing in breast cancer prevention research at the Mayo Clinic, tells BuzzFeed Life. You'll probably notice more lumps, breast pain, and tenderness as you approach your period, and it's most common between the ages of 20 and 50 (it usually calms down after menopause). Basically, it's totally normal and nothing to worry about. But if the pain gets worse or you notice new lumps that feel hard, irregular, and immovable, check it out with your doctor. 2. Coffee can make your boobs more sensitive. View this photo on Instagram instagram.com There is some evidence that caffeine may increase breast pain and tenderness, especially in people with fibrocystic breast changes, Dr. Elisa Port, chief of breast surgery at Mount Sinai Medical Center and the co-director of the Dubin Breast Center at Mount Sinai, tells BuzzFeed Life. But dedicated coffee drinkers might choose a little boob pain over living life uncaffeinated. So basically, do with that what you will. 3. Your workout could give you boob pain. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Paramount Pictures / Via reddit.com That achy breast pain might actually be muscle soreness behind your boob, says Pruthi. So if you've been doing lots of pushups or chest exercises, it could be your pectoral muscles that are really hurting. 4. Or your boobs could hurt for tons of different reasons. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Universal Pictures / Via gifs-andthings.tumblr.com Hormones are the common cause — whether it's a normal fluctuation from your cycle or pregnancy or a sensitivity to the estrogen in birth control pills or hormone therapy, says Pruthi. Some people are more sensitive to estrogen's effects than others, so it really depends on the person. But boob pain can also be caused by a lot of movement with an unsupportive bra, or you might be mistaking breast tenderness for pain on the chest wall or ribcage, says Pruthi. If it persists, gets worse, or only occurs in one breast, check that out with your doctor. 5. Nipplegasms exist. View this photo on Instagram instagram.com "Some people do experience orgasm from nipple stimulation alone," Debby Herbenick, Ph.D., author of The Coregasm Workout, previously told BuzzFeed Life. "It's rare, but it happens." 6. Boob size is pretty much all genetics and weight. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF FOX / Via fuckyeaharresteddevelopment.tumblr.com Whether you're an A cup or DD cup typically comes down to DNA and overall body size, says Pruhti. Since breasts contain fatty tissue, their size tends to go up and down when you gain and lose weight. 7. Anyone with breast tissue can get breast cancer. View this photo on Instagram instagram.com Women, men, cisgender, transgender — anyone with breast tissue can get breast cancer. About 1 in 8 women will get some form of breast cancer at some point in life, and the rate for men is about 1 in 1,000, according to the American Cancer Society. Male breasts are very similar to female breasts, though they typically have more fatty tissue than connective tissue because they're producing less estrogen, says Pruthi. But if they're exposed to estrogen in the form of medications or drugs they're taking, they may be more at risk for developing breast cancer. Although there aren't statistics available for the prevalence of breast cancer in transgender individuals, it's important to remember that anyone is at risk. If you're transitioning from a woman to a man, you can still get breast cancer as long as you still have breasts, says Pruthi. And if you're transitioning from a man to a woman and taking hormones, your doctor may advise you to follow the same breast cancer screening guidelines as cisgender women (we'll talk more about screening guidelines in a bit). 8. More than 80% of people who get breast cancer don't have any family history. View this photo on Instagram instagram.com They are their family history, says Pruthi. So don't assume that genetics are the be-all and end-all of breast cancer. 9. Nipples and areolae can come in all shapes, colors, and sizes. View this photo on Instagram instagram.com Whether your nips are big, small, dark, or light — they're normal! Your areola (the colored skin around your nipple) can also totally vary. Some people also have inverted nipples, which means they indent into the skin instead of pointing out. Basically, nipples are not one-size-fits-all, and they're all totally normal and great. (If you ever have a change in the appearance of your nipples though, that's something to see a doctor about.) 10. Your boobs won't automatically get bigger with birth control. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF EA Games / Via reddit.com Some people notice an increase in size while others stay the same, says Pruthi. Again, it depends on your weight, genetics, and how sensitive you are to the effects of the hormones in your birth control (or if your birth control method contains hormones at all). 11. Your boobs are made up of a few different things. View this photo on Instagram instagram.com Your breasts have a lot of functioning tissue, which includes the milk ducts and the lobules, says Port. There's also fibrous connective tissue to help hold everything together, and everything else is basically fat. 12. Your breast density is the relative amount of functioning tissue to fatty tissue. Bill Mulder / Creative Commons / Via Flickr: bilbord99 You've probably heard of dense breasts, which can be harder to read with a mammogram. This means that there's more functioning tissue (like milk ducts, lobules, and connective tissue) than fatty tissue. And your breasts actually become less dense as you get older, since you're producing less estrogen, says Pruthi. There's no way to know your breast density without a mammogram, but your doctor should tell you if you have them. 13. Saggy boobs are pretty much unavoidable. View this photo on Instagram instagram.com Again, blame aging. As you get older and stop producing estrogen, most of your milk glands and milk ducts regress and change into fatty tissue. This makes your breasts less dense, and it may even make them smaller and less firm, says Pruthi. Add to this the fact that your skin gets more elastic as you get older, and you're left with saggy boobs. Basically, gravity can be a cruel bitch. 14. Breast augmentations are still the top cosmetic surgery procedures. View this photo on Instagram instagram.com There were 286,254 of these in the U.S. in 2014, according to the American Society of Plastic Surgeons. That's a lot of implants. 15. Breastfeeding isn't always super easy and chill. View this photo on Instagram instagram.com "Breastfeeding can be incredibly difficult," Dr. Katharine O'Connell White, MPH, chief of the division of general OB-GYN at Bay State Health, previously told BuzzFeed Life. "People expect it to be natural and easy, but more patients than not have a lot of difficulty with it, which can leave them feeling really discouraged." If you're having trouble and want to make it work, lactation consultants at hospitals can help. Oh yeah, and breastfeeding can come with cracking, bleeding, and soreness on your nipples. O'Connell suggests Lanolin (or a similar ointment) to stay moisturized between feedings, but if that's not helping, you might want to check with your doctor since it's possible to get a yeast infection while breastfeeding (which hurts). 16. Your nipples can leak even if you're not breastfeeding. View this photo on Instagram instagram.com YUP, that can happen. It may be a normal response to getting your breast or nipple squeezed really hard (like when you're getting a mammogram), Port previously told BuzzFeed Life. But it could also be a sign of trouble, so see your doctor if it happens randomly, if it's bloody, or if it only happens on one breast. 17. Knowing what your normal boobs feel like is more important than a monthly self check. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF MTV / Via mtvgirlcode.tumblr.com According to the World Health Organization (WHO), there's no evidence that monthly breast self-exams are effective in screening for breast cancer. BUT most breast cancer experts strongly suggest feeling yourself up to know what your normal is. This is called breast self-awareness, and it's all about knowing what your boobs typically look and feel like throughout the day and throughout your menstrual cycle. There are a few ways to do this, but Pruthi suggests making a sweeping motion towards your nipple in a clock-face pattern. So starting at your collarbone (which would be 12 o'clock) and sweeping down to your nipple, then 1 o'clock, 2 o'clock, etc. The best way to stay on top of what's normal is to get familiar with your boobs once a month, ideally a week after your period (so you're not dealing with more fibrocystic breast changes). You're typically just going to be getting used to your boobs so you know when something is off. But if you happen to feel something hard, irregularly shaped, or fixed (it's not moving with your breast tissue but staying in one place), tell your doctor. Remember: These aren't hard and fast rules, says Port, but they may help you distinguish when something is off. 18. Chest exercises won't actually give you a perkier pair. Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Nicki Minaj Vevo / Via wifflegif.com Sure, this could build up the pectoral muscles, which sit behind your breasts. This ~could~ lift the chest wall (and maybe make your set appear a little larger), but there's no proof that it can actually affect perkiness, says Pruthi. 19. The side of your boob could be more sensitive than your nipples. View this photo on Instagram instagram.com Nips aren't always the star of the show. Sometimes its the tops, sides, or bottoms of the breasts, Herbenick told BuzzFeed Life. 20. Most people with breasts should start getting mammograms at age 40, but that's not always the case. Bartosz Wardziak / Getty Images / Via thinkstockphotos.com The American Cancer Society, the American College of Obstetrics and Gynecologists, and the National Comprehensive Cancer Network all recommend annual mammograms for women 40 and older. The U.S. Preventative Services Task Force does not recommend regular screening before age 50, but suggests making an individual decision with your doctor about when to begin screening. They do recommend mammograms every other year starting at age 50. So why all the contradictions and controversy? Well, some people worry that too many mammograms lead to unnecessary anxiety and false positives, while others value the added emphasis on early detection. Pruthi says she goes along with the recommendation to screen annually starting at 40, but she makes sure to counsel patients on the risks and limitations of mammograms — like that they don't find everything, and they could possibly lead to false positives or unnecessary biopsies.Some people at a higher risk of breast cancer may need to be screened even earlier. If you have a first-degree relative (mom, dad, sister, brother) with breast cancer, it's recommended that you start getting mammograms 10 years before the age that they were when they were diagnosed. (So if your mom was 45 when she got breast cancer, get screened at 35.) NOTE: There are not explicit recommendations for transgender individuals, but if you have breasts or you're taking hormones to transition to a woman, talk to your doctor about how often you should be screened. 21. Breast cancer screening isn't always done by mammograms. View this photo on Instagram instagram.com Mammograms are the most common screening tool, but they're not always the best or only choice. In women with dense breast tissue, it may be harder to find a tumor on a mammogram (because both tumors and dense breast tissue appear white on the test). In some cases, your doctor may also suggest an ultrasound, which has been shown to pick up on more cancers as well as more false positives. Women at a higher risk of breast cancer may also need to get an MRI, which may be able to pick up some cancers you could miss with the mammogram alone, says Pruthi. Another new screening tool that Pruthi is excited about is the 3D mammogram, or tomosynthesis, which may be able to give a better picture of the breast tissue and reduce the need for repeat visits, she says. 22. Drinking less alcohol and maintaining a healthy weight are two major ways to cut your risk of breast cancer. View this photo on Instagram instagram.com Research shows that the more alcohol you drink, the higher your risk of breast cancer, according to the National Cancer Institute. Another way to lower your risk is to stay at a healthy weight, since obesity increases the risk of getting breast cancer and the risk of recurrence if you've already had it, says Port. 23. Most boobs aren't the exact same size. View this photo on Instagram instagram.com It's totally normal if your breasts aren't perfectly symmetrical, says Pruthi. It could even vary as much as a cup size. But really, it's not uncommon. Whatever size/shape/color your boobs are, they're fucking awesome, we promise.