Dr Scott J Turner | Specialist Plastic Surgeon (FRACS)
Key Takeaways
- Some degree of difference between the breasts is close to universal. What makes it worth correcting is whether it is visible in clothing, affects bra fit, or bothers the person who has it.
- Asymmetry present since puberty is developmental. Asymmetry that is new or changing in an adult needs assessment before any discussion of surgery.
- Uneven breasts differ in more than size. Volume, shape, position, and nipple-areola differences each need identifying, because they call for different operations.
- Correction is tailored rather than standard. Augmentation, reduction, lift, fat grafting and areolar work are combined according to which parameters are affected.
- MBS item 45060 may apply where a developmental abnormality is documented with a volume difference of at least 20% in normally shaped breasts, or 10% in tubular breasts or breasts with abnormally high inframammary folds.
Almost no one has perfectly even breasts. Measurable differences in volume, shape or position are close to universal, and most women who have them never think about it. What brings people to consultation is when the difference is large enough to show in clothing, make bras fit badly on one side, or simply bother them.
One quick note before going further: if you have come here after seeing the word asymmetry on a mammogram report, that is a description of tissue density on imaging rather than of how the breasts look, and it is a question for your GP or the radiology service rather than a plastic surgeon. This guide is about visible differences in breast size, shape and position.
It covers what uneven breasts are, what causes them, when a difference needs medical assessment rather than cosmetic planning, how correction is planned, and where Medicare fits. Full detail on the operations themselves sits on the breast augmentation, breast lift and breast reduction pages.
What uneven breasts are
Breast asymmetry describes a visible or measurable difference between the two breasts in size, shape, position or nipple appearance. Minor differences are normal and present in most women. The clinical question is not whether a difference exists but whether it is significant enough to warrant correction, which depends on how large it is, whether it affects clothing and bra fit, and how much it matters to the person.
Types of breast asymmetry
The patterns cluster into a few recognisable types, and identifying which are present is what drives the surgical plan.
Volume asymmetry is the most common, where one breast is meaningfully larger. This is the type patients notice most, because it shows in clothing and bras.
Shape asymmetry means the breasts hold similar volume but differ in profile, projection or base width. This can look uneven without being about size at all.
Position asymmetry is when the breasts sit at different heights or angles on the chest wall, sometimes driven by the chest wall itself and sometimes by ptosis affecting one side more.
Nipple-areola asymmetry covers differences in nipple height, areolar size or nipple direction. Breast volume can match while one nipple sits higher or one areola is noticeably larger.
Combined asymmetry is the most common presentation in practice. Some volume difference, some position difference, perhaps areolar asymmetry as well. Mixed presentations are the rule rather than the exception.
What causes uneven breasts
The list is longer than most patients expect, and the cause matters because it changes both the surgical plan and whether Medicare applies.
Natural developmental variation is by far the most common. No two breasts develop identically, and most asymmetry has no underlying pathology and no triggering event.
Chest wall and skeletal differences are frequently missed. Scoliosis can rotate the rib cage and lift one side, pectus excavatum and pectus carinatum alter the platform the breasts sit on, rib prominence on one side changes projection, and differences in the pectoralis muscle affect shape. This matters because the breast tissue itself may be entirely symmetrical while the chest wall underneath is not, and no amount of work on the breast alone will fully even out a skeletal difference.
Developmental conditions. Tuberous breast deformity and Poland syndrome both produce asymmetry as part of how they present, and both are classified as developmental abnormalities rather than cosmetic concerns, which has Medicare implications. The tuberous condition is covered in full in the tubular and tuberous breasts guide.
Pregnancy and breastfeeding. Changes during pregnancy and feeding do not always reverse symmetrically. One breast may retain more volume or develop more skin laxity, so someone who started with matched breasts can finish with a meaningful difference.
Weight fluctuation. Breasts contain variable amounts of fatty tissue, and fat does not always redistribute evenly, so significant weight change can produce asymmetry that was not there before.
Previous surgery, trauma or radiation. Biopsies, lumpectomies, injury, and radiotherapy to one side all alter the shape and volume of the treated breast.
Benign breast conditions such as fibroadenomas, cysts and fibrocystic change can affect one breast more than the other.
Posture does not cause anatomical asymmetry, but some postural patterns make existing asymmetry look worse.
New or changing asymmetry in an adult
Asymmetry that has been present since puberty is developmental, and it is what most of this guide addresses. Asymmetry that is new, or that has changed in an adult whose breasts were previously even, is a different situation and needs assessment before any conversation about correction.
The changes that warrant prompt review are one breast becoming smaller and firmer, one breast enlarging rapidly, redness or skin thickening with a dimpled orange-peel texture, a new lump, nipple changes or discharge, and any change in a breast that had been stable for years. Some of these have benign explanations. Some do not, and the ones that do not are time-sensitive.
This is not a reason for alarm about long-standing unevenness, which is common and usually developmental. It is a reason to separate the two situations. Correction of a recently developed unilateral change is not planned until the causes that need excluding have been excluded. Routine breast screening should also continue at the recommended interval regardless of whether you are considering surgery.
How asymmetry is assessed at consultation
Assessing asymmetry properly takes a structured history, a detailed examination and measurements rather than a visual impression.
The history covers when the asymmetry was first noticed, whether it has changed, what happened around pregnancies or weight changes, any previous breast surgery or pathology, and what symptoms it causes.
The examination starts with the chest wall, since skeletal differences change what is achievable, then moves to measurements on each side: base width, projection, upper pole to nipple distance, nipple to fold distance, soft tissue quality, ptosis grade, and nipple-areola position, orientation and diameter. All of it is documented on standardised photographs in multiple views, which also provides the volumetric documentation any Medicare claim requires.
Correction surgery
Correction is tailored. There is no standard asymmetry operation, and the plan depends on which parameters need addressing.
Augmentation on the smaller side matches volume where the larger breast is already where the patient wants it.
Bilateral augmentation with different implant sizes places implants on both sides with a larger one on the smaller breast. Contemporary practice more often uses matched base-width implants with fat grafting added to address the volume difference, which tends to produce a better shape match than differing implant widths.
Reduction on the larger side is the reverse approach, used where the issue is that one breast is too large rather than the other too small.
A lift on the ptotic side can be the simpler fix where the asymmetry is mainly positional.
Fat grafting is useful for subtle volume differences and contour refinement, and is often combined with implants rather than used alone.
Areolar correction addresses differences in areolar size or nipple position using peri-areolar techniques on one or both sides.
Combined approaches cover most real cases: augmentation on one side plus a lift on the other, or bilateral augmentation with different volumes plus a unilateral lift. The plan is built around the specific pattern.
Results vary between individuals, and the degree of symmetry achievable depends on starting anatomy, particularly where a chest wall difference underlies the asymmetry. Perfect symmetry is not a realistic goal for anyone, since it does not exist naturally either.
Non-surgical options
Not everyone with asymmetry wants or needs surgery, and for mild cases several things help manage appearance.
A specialist bra fitting with removable pads or silicone inserts is underrated and can do a surprising amount for mild asymmetry under clothing. Postural work sometimes improves the appearance where habitual posture is emphasising it. Weight stabilisation is worth doing first where asymmetry has developed alongside ongoing weight change, both to prevent it worsening and to make surgical planning accurate if surgery is chosen later.
None of these change the underlying anatomy. They manage the visual impact of mild cases.
Medicare and item 45060
Most asymmetry correction is cosmetic and attracts no rebate. Where the asymmetry results from a documented developmental abnormality, MBS item 45060 may apply.
The criteria are specific. The correction must involve either bilateral mastopexy for symmetrical tubular breasts, or surgery on both breasts combining implants with at least a 10% volume difference between them, mastopexy or reduction mammaplasty. There must be a documented difference in breast volume of at least 20% in normally shaped breasts, or 10% in tubular breasts or breasts with abnormally high inframammary folds, demonstrated by an appropriate volumetric measurement technique. Photographic or diagnostic imaging evidence showing the clinical need must be documented in the patient notes. The item is claimable once per occasion of service.
Where correction is staged, item 45072 covers the second stage, exchanging tissue expanders for implants, under the same volume-difference thresholds. Unilateral procedures in the context of developmental abnormality fall under separate items again.
Two practical points. The volume-difference threshold is why measurement and standardised photography at consultation matter so much: without that documentation there is no claim, regardless of how uneven the breasts look. And an eligible item number matters more for activating private health cover toward the hospital component than for the Medicare rebate itself. Eligibility is determined at consultation against measurements, not from photographs sent in advance. Costs are individualised and set out in a written quote after assessment.
Consultation in Sydney
Consultations are held at the Bondi Junction rooms in the Eastern Suburbs and at Manly on the Northern Beaches. Surgery is performed in accredited private hospitals including Delmar Private, Bondi Junction Private and East Sydney Private.
A GP referral is required before an initial surgical consultation, a minimum of two consultations is required before booking, psychological factors are assessed with referral for formal evaluation where indicated, and a cooling-off period applies between consent and surgery. For asymmetry cases the first consultation is usually where the measurement and photographic documentation is completed, which is also what determines whether a Medicare pathway is open.
Frequently asked questions
Is it normal to have uneven breasts?
Yes. Some measurable difference between the breasts is close to universal, and most women have one breast slightly larger, higher or differently shaped. Asymmetry becomes clinically relevant when it is visible in clothing, affects how bras fit, or bothers the person enough to seek correction. A difference that has been present since puberty is developmental and normal.
Will my breasts be perfectly symmetrical after surgery?
No, and that is not the goal. Perfect symmetry does not occur naturally, and surgery aims to reduce the difference to the point where it is no longer noticeable in clothing or bothersome, rather than to produce a matched pair. How close a result is achievable depends on the starting anatomy, and particularly on whether a chest wall difference underlies the asymmetry, since that limits what work on the breast alone can correct.
When should I be worried about breast asymmetry?
Long-standing unevenness is usually developmental and not a concern. What warrants prompt assessment is asymmetry that is new or changing in an adult, particularly one breast becoming smaller and firmer, one enlarging rapidly, redness with skin thickening or an orange-peel texture, a new lump, or nipple changes. These need investigation before any discussion of cosmetic correction.
Can breast asymmetry be corrected in one operation?
Usually yes. Most cases are addressed in a single procedure combining whichever techniques the pattern requires, such as augmentation on one side with a lift on the other. Staged correction is occasionally needed where the difference is severe or where tissue expansion is required first, and that is one of the situations MBS item 45072 covers.
Will Medicare cover my asymmetry correction?
Only where a developmental abnormality is documented and the criteria for item 45060 are met, which require a volume difference of at least 20% in normally shaped breasts or 10% in tubular breasts or breasts with abnormally high inframammary folds, demonstrated by volumetric measurement and supported by photographic or imaging evidence in your notes. Asymmetry from pregnancy, weight change or natural variation does not generally qualify. Eligibility is assessed at consultation.
Dr Scott J Turner is a Specialist Plastic Surgeon (FRACS) consulting in Sydney. A GP referral is required before an initial surgical consultation under the current Medical Board of Australia framework. Which combination of procedures suits a given case depends on which parameters differ and by how much, measured against your own anatomy rather than estimated from appearance, so to have that assessed properly, contact the practice to arrange a consultation.
