What Causes Uneven Boobs?

 a woman’s torso wearing green bralette, green underwear, and green blazer

Have you ever looked down and realized you have uneven boobs? Maybe one is a full cup size bigger and creates more boob sweat, or one just hangs a little bit lower. Either way, it can be alarming. And it can make it hard to find the right size of bras (especially triangle bralette styles).

If this sounds like you, then you probably want to know, “why are my boobs uneven?” Well, I’m here to clear the air. Just like how our breast shapes can all be different, sometimes our individual breast sizes are too! But that can happen for a few different reasons—-some serious and some no big deal. Let’s break it down some more below.


 infographic depicting different breasts shapes

Usually, uneven boobs are when your boobs are two different sizes. However, you may have lopsided tits because of different positioning, shapes, or sagging.

Many people notice uneven tits during puberty. This is pretty normal and they should even out by the time you’re about 16. However, if they haven’t evened out by 21, there’s a good chance you’ll have uneven boobs long-term.

If this is you, then welcome to the club! About 25% of people with breasts have noticeably lopsided tits. And up to 90% of people have a 15-20% difference in their boob sizes. So you’re not alone and it’s certainly not weird. All boobs are different and yours will continue to change slightly over your lifetime.

Plus, if you’re worried about breastfeeding with uneven boobs, don’t be. The unevenness comes from different amounts and positions of fat in your boobs. It has nothing to do with your milk ducts.


 sitting woman in a black bralette and underwear with short dark hair

There are a few different reasons for uneven boobs:

  • Hormones: your hormones rule your body during puberty as your boobs are growing (and, um, kind of all the time…oh womanhood!). Sometimes, these pesky hormones cause one breast to start growing before the other, and the later one doesn't always catch up.
  • Menstruation: breasts are typically less symmetrical during your period and ovulation because of the changes your boobs go through (those hormones again!). For example, during ovulation, boobs tend to swell, and not always evenly. On the other hand, during your period, your boobs shrink (again, not always evenly).
  • Injuries: if you suffered any injuries to your chest during puberty, it can permanently change your breasts. Many times, people involved in sports during early adolescence see this.
 woman’s back with scoliosis with a rainbow flag painted on it
  • Skeletal conditions: medical conditions like Poland Syndrome, funnel chest, or scoliosis can cause uneven boobs because your skeletal system is uneven underneath.
  • Juvenile hypertrophy: a physically harmless condition where during puberty, one breast grows very large at a rapid rate while the other one does not. It’s not dangerous, but it can be difficult to deal with psychologically, especially because it happens at such a fragile time for our psyches.

For most of these causes, uneven boobs are not a serious condition. Yes, conditions like scoliosis are painful, but the symptom of uneven boobs is not the issue at hand. However, there are times when uneven boobs can be a sign of a more serious underlying condition.


a doctor in a white coat talking to a patient sitting on a table

Before we dive in, it’s important to remember that I am not a medical professional. And while the information you’re about to read may be concerning, you should talk to your doctor before jumping to conclusions.

Uneven boobs in general is not a life threatening or dangerous condition. However, if you have noticed a sudden unevenness in your boobs, you should see your primary care physician.

Most of the time, changes in your breasts are completely normal. Sometimes though, it can be a sign of breast cancer. That can look like one boob becoming denser, or new lumps that change the size or shape of one of your breasts.

Again, don’t rely on this blog post for medical advice or a diagnosis. Instead, reach out to a medical professional for the next steps. For US-based readers, the Centers for Disease Control and Prevention’s (CDC) National Breast and Cervical Cancer Early Detection Program (NBCCEDP) offers free or reduced cost screenings!


woman in the woods in a black bra and green undies with her heads above her head from the side

First of all, there is nothing wrong with your body because you have uneven boobs. If my eyebrows can be sisters and not twins, then my boobs can be too! So there’s nothing you need to “fix” about your body.

However, I also recognize that insecurities about uneven boobs can make getting dressed, finding comfy bras, and feeling confident more difficult for more people. And I’m not here to tell you how you should feel about your body. So if you’re looking for ways to even out those boobs, keep reading!


 woman wearing padded bra and jeans

Padded bras can be a great option for uneven boobs. The key is to look for padded bras with removable padding. Then, remove the padding from the side of your bigger boob. And voila, your boobs will look a lot more even.

This may not work if your boobs are completely different sizes though, so your results may vary. And if you’re not the biggest fan of wired bras (which most padded bras are), then this may not be your favorite everyday solution.


Rather than having to buy a bunch of padded bras, you can also check out balancing breast pads to even you out. They’re smaller, rounded pads, usually made of soft cotton or gel that you wear on your smaller boob. You can wear them in almost every type of bra, which makes them way more flexible.


 woman taking a mirror selfie in a black bralette, cream shirt, and jeans

In the bralette vs bra debate, bralettes are a clear winner for uneven tits. Because they aren’t lined or overly structured, they can lessen the emphasis on any unevenness. And they can be WAY more comfy thanks to how flexible they are, especially ones made of stretchy and soft materials like hemp fabric.

Styles, like racerback bralette styles, where it’s one piece of fabric across, are the best because everything sorts of settles together in there. Triangle bralettes may reveal a bit more unevenness because of the separate cups for each boob.


a gloved surgeon opens gauze on a surgical table

For some people, surgery is the path they want to follow. And for some conditions, surgery also makes the most sense. For example, having juvenile hypertrophy can cause serious psychological harm and physical pain. No breast pad is going to remedy that. So talk to your doctor about your options if that’s something you’re considering!


Finally, what if you just rocked those lopsided tits like the gorgeous tatas they are? Every body is different and yours just happens to come with uneven boobs! So if you're tired of trying to change what they look like for how they hang, just don’t. Put on your most form-fitting top and reveal those beautiful uneven tits to the world (just don’t reveal enough to get written up).


woman adjusts black bralette and leans against a white wall

Even though you may not exactly love your uneven boobs, most likely they’re totally harmless. And every unique part of your body is what makes you so special to the world. That may seem crazy, but it’s true. All of your special differences add up to a beautiful human worthy of feeling good about yourself.

If you’re worried about what's causing your uneven boobs, though, don’t hesitate to talk to your doctor. It’s always better to be safe rather than sorry. And it’s always, always better to trust a medical professional with your health over an underwear blog writer (even though I do know a lot!).

Just like how all breasts are different shapes and sizes, we also all have different butt shapes. So my question is: would you rather have uneven boobs or uneven cheeks? Let me know in the comments below!

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