top of page
  • Writer's pictureEvenly

Why Is One Breast Bigger Than The Other?

Despite what the media may have you believe, having one breast bigger than the other is perfectly NORMAL. In fact, many studies show all women have some degree of natural breast asymmetry. We explore the causes of uneven breasts and solutions to help.

Let’s face it, bra shopping can be a pretty torturous experience, right? A seemingly never-ending quest to find that mythical unicorn that is the perfectly fitting bra. Especially when you have one boob bigger than the other!

For many, finding lingerie that fits well can be a painful experience - quite literally! An uneven chest can lead to neck and back problems as well as posture issues, which can then be exacerbated by an ill-fitting bra…. it makes us dizzy just thinking about the circles we can go in.

Evenly has been founded by a fellow member of the Uneven Titty Committee to help make our boob-related inequality a lot more manageable, with a simple solution which brings balance to your bra. Hoorah!

It's Not You, It's Everyone

Despite what mainstream media, some Instagram influencers and lingerie advertising execs may have you believe, breast asymmetry is perfectly NORMAL. In fact, many studies show all women experience some degree of natural breast asymmetry, ranging from barely perceptible differences to inequalities of a few cups sizes or more. Some size differences rarely change post-puberty, whilst others fluctuate constantly day to day, month to month, or even hour to hour (holla to all the breast-feeding mums!) Whilst many of us here may have the imbalance in common, there are a plethora of reasons why people develop one breast larger than the other.

Mother Nature Has a Lot To Answer For

Our hormones are one major culprit. During puberty, pregnancy, breast-feeding, menopause or throughout the monthly cycle, our bodies change like the seasons and this can manifest most visibly in our breasts. Our breasts are home to a significant number of our body's fat cells, so lifestyle changes and weight gain or loss will also often lead to big jumps in bra balance too.

Between 5% and 10% of breast asymmetry cases show severe differences in breast sizes. There are several genetic conditions that can cause larger imbalances, such as Poland Syndrome, a congenital condition where pectoral muscles do not develop fully on one side of the body, leaving the overlying breast on that side much smaller. There is also Breast Hypoplasia, also known as Tubular Breasts, which occurs most commonly in puberty and can affect the growth of one or both breasts. Additionally Amastia (or Amazia) can also affect breast tissue development.

For others uneven breasts are the result of surviving breast cancer - something undoubtedly to be celebrated - but which may have resulted in breast tissue being removed, with mastectomy, lumpectomy or therapeutic mammoplasty surgery resulting in larger imbalances amounting to a full breast or several cup sizes’ difference.

For many of us though there is no obvious cause, it is simply nature in all it’s beautiful mystery and uniqueness. 62% of people with asymmetry have a fuller cup on the left hand side, which simply could be attributed to the tissue surrounding your heart. We like to think of these as the people with especially big hearts.

It's a Pain in the Neck

Breast asymmetry is more than just an unevenness of the chest. It can also cause great psychological discomfort and feelings of self-consciousness. Often these differences in breast size are not noticeable to others, but of course there is always a tendency to notice these things more on our own bodies (ain't that the truth).

As if feeling self-conscious isn’t enough, the imbalance might also lead to that gorgeous bra you just bought not quite fitting properly. Our lopsided bosom might either create a bulging ‘muffin top’ boob on one side, or a huge crumb-collecting gape on the other. Not to mention straps that dig in more on one side, a band that slides up and all the neck and shoulder pain to go with it.

How We Can Help

Fix uneven boobs

Plenty of people opt for cosmetic breast surgery, which may be something you are considering. But if you want to avoid the surgeon’s knife and still give your girls the balanced support they need, Evenly has your back (and your neck and shoulders)!

Our solution for getting a good fit is to buy a bra you love which accommodates your fullest cup, and add in your Evenly Bra Balancer to even out the smaller side. Yep, it really is that simple. The shape and fluid feel of the silicone provides a smooth, natural and balanced appearance. It's also superbly weighted to mimic the weight of the missing natural breast tissue, meaning your bra can hold and distribute the weight of your breasts more evenly - clever huh?

Get It Off Your Chest

Whatever the reason for your breast asymmetry, Evenly is here to support you (see what we did there) and to bring more balance to your bra.

If you’d like to share your experiences with other members of The Uneven Titty Committee you can do so in our private and safe Facebook group.

Team Evenly xx



Oct 09, 2021

This sounds like the answer to my prayers following a mastectomy and reconstruction which looks amazing but doesn’t *quite* match the original in size. Thank you!

Oct 13, 2021
Replying to

Fantastic, thanks Slyvia! Please let us know if you'd like any help with finding your perfect size.


Sep 17, 2020

Thanks for dropping by Sara! ✌


Sep 17, 2020

Well written! Thanks for sharing ❤️

bottom of page