Breast Tissue Migration: Fact or Fiction?

By Ali Cudby

Recently, a bra blogger asked if a particular fit problem could be attributed to breast tissue migration.  That question prompted me to research the topic, because we owe it to our customers to understand the fit issues being discussed in the world.


Breast tissue migration has not been covered in my online bra fit school for professionals, The FabFit Academy, because I didn’t previously have an informed opinion on the topic.  After speaking with both the bra blogging community and the medical community, I have a better understanding of what breast tissue migration is (and isn’t) and how it affects the subject that is the core of your business as a lingerie retailer, namely, how bras fit.

Breast tissue migration seems to be most commonly defined as “breast tissue that is semi-permanently redistributed to the armpit and/or back area, as the result of an ill-fitting bra.” Overall, the argument is that wearing a properly fitting bra over a period of weeks or months will redistribute breast tissue from its migrated position to its natural home in the “cup” area of the breast and, by extension, the bra.


The origin of the breast tissue migration theory seems to stem from Polish bra bloggers.  The earliest reference I found was from the Venusian Glow blog in September 2009.  The blog post states that, “the breasts sneak out of the too-small cups into the armpit area.  Presto! Instant armpit rolls! Very often, migration doesn’t stop here. Breast tissue, unchecked by the loose band, wanders further away…and ends up as back rolls.”  Venusian Glow author Eternal Voyageur shared that the phenomenon is widely discussed in Polish bra blogging circles.  She directed me to a Polish blog (also from 2009) that walks through the breast tissue migration phenomenon.

Since these blog posts, American bra bloggers and many consumers have shared robust support for the theory.

My understanding is that breast tissue migration suggests three components, all of which must exist in order to prove the theory.

1)     An ill-fitting bra can cause breast tissue to spill into non-cup areas of the body
2)     This “spillage” can go a) toward the armpit/underarm areas and/or b) find its way to a woman’s back
3)     The effect is actually a semi-permanent migration, reversed only by wearing a properly fitting bra for
several weeks.

Let’s break these claims down, one by one:

Claim #1: An ill-fitting bra can cause breast tissue to spill into non-cup areas of the body

This notion makes perfect sense.  When a bra cup is too small, the excess breast tissue has to go somewhere.  After all, it boils down to basic scientific principles.  If you are trying to put more units of volume into a container that is too small, there will be overflow.  In this case, breasts encased in a too-small cup will spill into a variety of places, including the underarm.

Claim #2: Spillage can go toward the armpit/underarm area

According to Rebecca Kaltman, MD Oncologist at George Washington University, there is a biological basis for seeing breast tissue under the armpit area.  Says Kaltman, “Under normal conditions, breast tissue extends up toward the axilla (the under arm) and is called the ‘Axillary Tail of Spence.’  This is not ‘migrated breast tissue,’ just actual breast tissue that extends beyond where most people feel the breast tissue might go.” So claim #2a seems to pass the sniff test, as well, since it’s reasonable to find breast tissue under the armpit and in the fold between the shoulder and the chest wall.

armpit - venentian glowLet’s look at claim #2b, the notion that rolls on the back are actually breast tissue.  A look at the photos in the Venusian Glow blog post from 2009, reveals some excellent examples of ways that bra fit itself can impact bodily appearance.  A band that’s too loose can ride up, pushing the flesh on the back into rolls that appear to be “back fat.”  It’s the fit that creates the unflattering look.   (photos via Venusian Glow)

A band that’s too thin can further complicate fit issues
to create unsightly bulges.

(photos via Venusian Glow)

This back flesh is not breast tissue, migrated or otherwise.  There is simply no biological basis for breast tissue to travel to the areas of the back indicated in these photos.  A properly fitting bra can alter the appearance of back flesh, but does not redistribute it in any real sense of the word.

Claim #3: Breast Tissue Migration is actually a semi-permanent migration

The crux of the breast tissue migration theory is that the movement is a physical manifestation from years of wearing ill-fitting bras.  The bra blogger community’s, “proof for is that when women get their first perfectly-fitting bras and are taught to regularly scoop and swoop, often after a few weeks they need to go up a cup size. Obviously new bras don’t make breasts grow, so the only explanation is that the migrated tissue has returned to the cup,” according to Suchocka-Mohr.

Elisabeth Dale, breast expert and Founder of The Breast Life, is skeptical.  “If a bra could, by way of lifting, improve our breasts, then why would any woman ever have a lift?  A bra can’t do much but make you look better in your clothes. And any woman who has worn a push-up or padded one knows it’s all an optical illusion.”

Dale’s observation raises an excellent point.  If an improperly fitting bra creates a negative effect, then the biology should work both ways.  If breast tissue is “moldable,” it would seem to suggest that we could migrate breast tissue up and in after wearing a push up bra for an extended period of time.  Or make the breasts pointy by wearing a bullet bra.  But nobody is making that argument about breast tissue.

One caveat from the medical side is an observation from Plastic Surgeon Byron Poindexter, of Austin Weston Center for Cosmetic Surgery in Virginia, “from the surgical perspective we can see patients after surgery that are in a more ‘moldable’ state and garments or clothing that they wear after surgery can have a more permanent effect on their shape.  But these patients have had a temporary disruption of the normal skin and fat structures that hold us all together that allows this to happen.”

When asked about the idea of other, unaltered breast tissue behaving in the same way, Dr. Poindexter unequivocally does not see it as a possibility .  “I do see patients who have concerns of ‘hangover’ of  tissue in the armpit area, or on the back,” says Dr. Poindexter. “This is not breast tissue that has been permanently pushed there. Rather, it is breast tissue or fat that is naturally there that may be temporarily exaggerated due to and while wearing garments like poor-fitting bras. I am not aware of any evidence to support this type of ‘migration.’  It also doesn’t really fit with what we know about the breast anatomically or how it changes through time.  We would love it if there were a way to utilize a garment to permanently restructure an area, but it just doesn’t happen.  Breast tissue really just wants to go one way, and that is down where gravity is pulling it.  If an ill-fitting bra worked to migrate tissue out into an armpit, then a good fitting one would be able to migrate it up and keep it on the chest.”

In summary, the medical community and the bra blogger community disagree about the existence of breast tissue migration as a semi-permanent manifestation of wearing an ill-fitting bra

After having thought about the topic for an extended period of time, there are aspects of the breast tissue migration theory that are troubling.  The theory – and several of the bra blog posts I’ve seen on the topic – seems to suggest that women should have no armpit flesh or bulges in any location near their bra.  That seems like an unrealistically high standard with too much potential for body shaming.  Women already suffer from body image issues.  The byproduct of believing in breast tissue migration could end up exacerbating the problem.

There are simply too many differences in women from body to body.  I have seen plenty of women who wear properly fitting bras and who also have some extra flesh in the armpit region.  If we send the message that bras “should” reverse what biology decrees, do we run the risk of undermining both women’s self-confidence and our own mission as fitters?

What’s your take on breast tissue migration?


27 Discussion to this post

  1. Sam says:

    So I personally have Auxilary Breast Tissue that is so robust it could easily fit into an A cup. It is NOT a fold and I’ve had it since Ive developed anything. The type of bra I wear CANNOT do anything to change this because there are no bras currently made that would even fit with this tissue. I’ve had doctor after doctor look and unfortunately Insurance will not cover the removal so it is a PAIN IN MY BUTT to try and find bras to fit.

    • molly says:

      Literally same! the removal would be considered cosmetic and costs a shit ton:( not only does it make me super self conscious (i also have an a cup and its literally the same size as my actual boobs) but it also swells up sometimes and which is super uncomfortable

  2. David says:

    I don’t know anything about medical research (breast ultrasounds and histopathology). I know, that many doctors don’t check armpit folds during during breast ultrasound examination. For many women and for many doctors, they are natural parts of breasts. I waiting for one ultrasound doctor, who will check this on the group of volunteers who wear padded push-up bras and they have “folds-symptoms of breast tissue migration”.

  3. […] want to live a life in which I was obsessed with food and my bodily proportions. Due to tissue migration (which may or may not be real), I’ve grown to a 36K/KK, which was ironically my original […]

  4. […] de Lingerie Briefs se montre en revanche beaucoup plus sceptique dans son article « Breast Tissue Migration: Fact or Fiction?« . Elle déclare avoir interrogé des professionnels de la santé sur 3 idées qui […]

  5. Ro says:

    I’m 19 and have exta/cut off breast tissue in my tale of spence and it bulges out in every bra I wear and can’t seem to find a single one that fits because of it. I looked at old pictures when my breasts were smaller (I went up 2 cup sizes a little over a year ago) and I didn’t used to have it and based on everything written here, i’m definitely a believer in tissue migration. especially when it’s out of the tightest part of the bra, it just cuts it off in my own experience. Anyways, I’ve been “scooping and swooping” for a couple days now and it’s driving me mad but I think after a few months of wearing a better bra (one that I might have to order because my size doesn’t technically exist), I’d be happy to post any results if this forum is even still active… thanks for putting all this up! what a relief to know my problems are 1-possibly only semi-permanent, and 2- not uncommon.

  6. […] comes to avoiding armpit fat! In fact, some people believe that almost all armpit fat is actually migrated breast tissue, which is caused by wearing a bra that is too small. Don’t be afraid to go up a size in […]

  7. k says:

    I don’t understand-of course breast migration exists! Don’t women wear wasp waist corsets to change the shape of their waist? And that is a semi-permanent change that, after some time wearing the waist training corset, actually changes the shape of the waist even when not worn. Wouldn’t the same hold true of bras?

    • Ali Cudby says:

      Not all body parts behave in the same way. A corset – with its proven ability to reshape the waist – is not the same structurally as breast tissue, so these aren’t really apples and apples. The corset actually pushes internal organs around, to make room for the wasp waist of the corset. There are no organs to move when it comes to a bra, just the fat and glands, which behave differently.

      A better example might be wearing a too-tight ring on a finger, although the doctor I interviewed for this article said specifically that fingers and bras were not the same from a body composition perspective, either.

      I appreciate your question.

  8. SnarkMouse says:

    I get as frustrated as anyone else when someone argues from a position that defies known physical and scientific evidence (*cough*Jenny McCarthy vaccine nonsense wackjob*cough*)…but I also don’t think we should completely throw out the feedback of the many women who’ve experienced something akin to tissue migration, either. History is full of examples of women’s symptoms and experiences being dismissed and pooh-poohed by the medical community, only to be “discovered as actually true!” by some male doctor decades later. Women are *still* less likely to be diagnosed with heart ailments, and depression, and sleep apnea, and on and on and on, (even by female doctors) simply because they don’t fit into the androcentric medical model that is taught in medical school, and women are *still* routinely told that we’re imagining things, or getting hysterical, or “too emotional” to really understand unless it’s mansplained to us. I’m all for medicine and science over internet hypothesizing…but let’s face it: medicine and science don’t have a great track record of validating and incorporating women’s self-reports and experiences, no matter how compelling or numerous.

    Now, I do agree that we probably don’t need to blame every single body roll on “migrated breast tissue.” It’s unrealistic to think that women will be Barbie-like “tits-on-a-stick,” or literally skin-and-bones except for the breast and hip areas. Fat is, after all, a component of breast tissue, and for naturally large breasts, it’s unlikely that the fat cells will appear only on the front of the chest and nowhere else, even in a slender woman. I think you’re making an important distinction between appearance/temporary distribution of breast tissue, and actual permanent physical migration of the tissue itself. Of course, if it could be scientifically proven that bras *can* permanently alter breast tissue, bras would probably then have to be classified as medical devices, and we’d have to get brassiere prescriptions and they’d get even more expensive than they already are, so maybe the “scientific proof” road is best left untrod.

    One strong objection I do have is that Dr. Poindexter’s take on the matter basically works out to recommending cosmetic surgery for every possible bra-fitting issue: liposuction, breast reduction and lifts, and even “fat grafts” for bra strap indentations on the shoulders (which is clearly a mark of an ill-fitting bra). Color me shocked that a plastic surgeon goes straight to the “pay big $$$ to fix that!” explanation. He doesn’t have female-sized breasts, he doesn’t wear a bra every day of his life, he didn’t grow up trying to figure out bra sizing and observing changes in breast tissue first hand (and he doesn’t even have one female doctor on staff who might offer first-hand experience with such things)…but he does make a mighty good living nipping and tucking bodies. He’s hardly an unbiased party with no vested interest, here.

    • Ali Cudby says:

      I appreciate your thoughtful reply. I actually don’t think I am throwing out the experiences of women in the article, and actually took pains not to adjudicate one way or the other – for exactly the reasons you articulate here. There are aspects of the argument that I categorically don’t agree with (that flesh in the center of a woman’s back is actually breast tissue). I also don’t agree that Dr. Poindexter is suggesting “cosmetic surgery for every possible bra-fitting issue.” That wasn’t my read of what he said.

      As mentioned in previous comments, I would love to see evidence of breast tissue migration. I have heard lots of anecdotal stories, and I have seen pictures of women in bras – these just don’t add up to enough evidence for me, personally.

      Frankly, breast tissue migration has been tossed around as fact without a lot of scrutiny, and I continue to worry about the body shaming effects for women who simply have extra flesh in various places on their bodies. More information and a more rigorous approach is needed.

      Thanks so much for your comment!

  9. […] recently asked by leading bra fit expert Ali Cudby, known as America’s #1 Bra Coach, to comment on a question increasingly common in the retail lingerie community and on bra […]

  10. Vicky80 says:

    I’d raise some points:
    1. pointy breasts – has this doctor seen playboy playmates from 1950-1960 or so? I came across once and this ladies berast were all more pointy than it’s now, and I am meaning pointy, no “normal breast with no silicone”.

    2. after wearing a good fitting bra a breast shape can little bit or a lot change – can be more uplifted or more round, it can be “only” few cm, but it makes a change, maybe in some cases not a miracle, but still a good change. Example from polish brafitters coach, Maheda:

    3.Look at 3pictures – no6 (under “what matters is a horizontal band”). I have seen this woman in reality after 2years waering the good bra, as you can see her breasts changed a LOT. nobody will tell me that migration does not exist and bra cannot form the breasts after a while.
    Also a wrong push up bra can make your breasts flat if the size is really bad. and it also can be reversed to some point:)

    I am not talking about moving the fat tissue from the back but simply from all around the breasts.

    • Pru says:

      Womens’ breasts have NOT changed shape since the 60’s, but beauty standards HAVE. That is why you see different breast shapes, tans, and pubic hair styles in old Playboy issues versus current Playboy issues. Playboy IS NOT an accurate sample of the average American woman. My breasts have been several different sizes over my lifetime, and I’m just one woman.
      Womens’ bodies exist in tons of different shapes and proportions and always have, and always will. Our glossy mags just choose to focus on one body type at a time. Do you think that 50 years from now, someone will find an old stack of magazines and think all women from the 2000’s were skinny and waxed?

      • Ali Cudby says:

        Thanks to both Vicky and Pru for the excellent comments.

        There is a difference between what a bra can do to the appearance of breast tissue and what happens to the breast tissue itself. It’s simply not possible to make any significant assessment of the woman in the blog post’s breasts based on those photos. There are too many external factors at play.


  11. Ali Cudby says:

    Hi Margarita,
    I’m thrilled to see members of the style community sharing the importance of properly fitting bras. Bras go to the core of how women look AND feel in their bodies, every day.

    Please keep in touch – you can find me at or


  12. Margarita says:

    Thank you for your fantastic post. As a International style coach, i feel this message is so important to get out there. Ill fitting bras do us absolutely no favors, and create the opposite look of being polished. I don’t know how many times I see women with mono boobs because their cup is too small. The same with unsightly bulges at the back through t-shirts. It doesn’t matter what size one is across the back as long as the fit is right. If one goes up a size, they must learn to love themselves for who they are now, and get a bigger size. So many times, I see and hear women wanting a smaller size because they Used to be that size…. so once again Ali, thank you. i am so glad I came across your site. I hope to meet with you one day and learn more about your school.

    Warm regards

    Margarita Politis

  13. Melissa says:

    My take on this.. I am a Professional Bra fitter and own Bare Essentials. In daily life i come across this so called ‘migrated breast tissue’, i believe it is true and i would relate it to wearing a tight fitting pair of pants for a long period of time (weeks / months) The fat distribution does end up separating and making a dent in your belly. Trust me, i have seen this happen too. So i guess thats the only real way i can explain it. And by experience of seeing women that have bigger breasts that have been wearing the wrong size for years, there is a bulge under the armpit area, and wearing a bigger cup size helps this, you can also smooth the tissue back into the cups and over time it does migrate back..

    • Ali Cudby says:

      Hi Melissa,
      You are not the only person sharing stories like this, and I’d love to see it documented in a scientifically rigorous way. I would love to write a follow up article showing what you’re talking about, and taking the bras themselves out of the equation – purely looking for changes in breast tissue over time.


  14. confessionsofacurvygirl says:

    Breast tissue migration makes sense to me. Wearing the wrong size bra for a lot of women means their band size is too large and their cup size is too small. The underwires are made of metal and that metal pushes on the breast tissue.

    I recently read a thread on a A Bra That FIts sub reddit, where some of the posters wondered why their measurements change a few months after getting properly fitted.

    • Ali Cudby says:

      I have seen the comments on the sub reedit. It’s important to remember that the commenters there tend to be individuals who are talking about what they observe on their own bodies — hardly a scientific approach. Documentation I have seen about breast tissue migration has shown women in bras, when the theory essentially requires the change to happen to the breasts themselves. I would be interested to see a more regimented approach to documenting what people are talking about. I deliberately left the door open for this in the article, but something more rigorous than anecdotal stories are needed.

      Thanks for the comment!

  15. a_r says:

    Did the professionals that you contacted offer an alternate explanation for the changes that many women experience after finding a better bra size?

    • Ali Cudby says:

      There are alternate explanations – that women get better or more practiced with “swooping and scooping” for one. None of these were endorsed by the medical experts I interviewed, because they simply reject the theory of breast tissue migration.


  16. noys says:

    I have always rolled my eyes at the idea that back fat can be breast tissue (except in a very few cases of extremely wide breasts roots) but when a badly fitting bra pushes breast tissue towards your armpits it also pushes the fat that is already in the armpits slightly more towards the back. Anyone can easily simulate it on their bodies!

    • Ali Cudby says:

      I think there’s a difference between the effects of where a person can “squish” the flesh on their body, and what makes a semi-permanent change. Breast tissue migration suggests that the flesh will stay put, and that’s the aspect the medical community challenges.

      Thanks for your comment!

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