Micromastia and breast asymmetry

What is micromastia?

Micromastia effects more than half the female population who have experienced asymmetrical breast development during teenage years. (1) A disparity in breast size is common post-adolescence too, with a 15 to 20 per cent difference between breasts considered average. (2)

However, sometimes instances occur when asymmetry becomes highly developed or the breasts remain extremely small even post-puberty. The latter’s medical term for this is micromastia, which is the post pubertal underdevelopment of a woman’s breast tissue. This is also sometimes referred to as breast hypoplasia. Women suffering with this condition basically have two nipples on a flat chest rather than developed mammary glands.

There are two types of micromastia: bilateral and unilateral. Bilateral is when there is no breast tissue on either side of the chest. Unilateral is when there is breast tissue on one side and none or a significantly smaller amount of tissue on the other side.

Many women have asymmetrical breasts as a result of micromastia and while these conditions are not uncommon, they can have an enormous impact on a woman’s self-esteem and confidence.

What causes micromastia?

Some of the causes of micromastia can be related to congenital defects present at birth, such as abnormalities in the pectoral muscles. They may be evident when a child is born (for example; in the case of Poland syndrome where part of the chest wall muscle is missing), or may only become apparent in adolescence (for example; mammary hypoplasia or hyperplasia, or breast asymmetries).

Lifestyle factors in later life can also enhance asymmetry of underdeveloped breasts. When it comes to breastfeeding, it doesn’t matter how much you try to feed the baby evenly from both breasts, the child will often prefer one over the other. The end result – one of the breasts will stretch and appear uneven as time passes. The appearance of the larger breast can last long after breastfeeding has been completed.

Body alignment can play a role in breast asymmetry. The fat deposits and muscles in the body tend to become more evenly distributed when the body is in perfect alignment. The truth however is that during a person’s life, sleeping positions, injuries, stress, and posture, will cause body alignment to change and this over-development of the muscles causes fat tissue in the breasts to appear uneven.

Breast deformities can also be acquired as a result of trauma, burns, tumours, infection or endocrine dysfunction.

How serious cases can be treated

The best procedures to remedy severe micromastia usually involve uneven breast surgery. One of the options available is breast augmentation with implant or breast augmentation without surgery.

Breast implant surgery can address the problems of both bilateral and unilateral micromastia. The surgeon will advise on the appropriate size, shape and position of the implants. For bilateral micromastia, both the implants will be the same size. For unilateral micromastia, the surgeon will use implants that will help the breasts appear as similar in size as possible. Gummy bear or regular silicone gel implants create the most natural looking results in women with very little breast tissue, as these implants have a decreased chance of rippling.

However, if significant asymmetry has occurred as well, a combination of breast reduction, breast uplift and nipple repositioning might also be necessary. To correct asymmetry you have to try and make the breasts as similar as possible. Depending on each case, it might mean making the smaller breast bigger, the bigger breast smaller and correcting nipple position and size. There is a tendency for patients to request the smaller breast to be larger, but often the better symmetry is achieved in reducing the larger breast to the smaller breast.

More often than not, if you are trying to make your breasts appear more even, you will not only have to change one side, but will usually require uneven breasts surgery on the other side too. If you’re having a consultation don’t be surprised if you have to have operations on both breasts.

This is because you’re trying to make two breasts behave in a similar manner to each other.

Some of the issues to consider

General issues with breast surgery can involve scarring, possible interference with breast feeding and sometimes a risk to the nipple itself in terms of its blood supply. When it comes to obvious asymmetry, there’s a need for surgeons to thoroughly check a patient’s breasts prior to surgery. This is because some research suggests breast asymmetry may be a sign of increased risk of breast cancer. (3)

In order to detect any signs of cancer we would commonly advise getting either an ultrasound or mammogram pre-op. The purpose of this is to detect any significant disorder of the breast(s) prior to surgery, so the problem can be resolved beforehand.

The incidences of new breast cancer cases are increasing at a yearly rate. (4) It is essential to detect an early cancer so cosmetic procedures do not distort and diminish the opportunity for cure, or limit the usefulness of lumpectomy in cancer treatment. If you are between 18 to 40 years’ old we recommend patients get an ultrasound prior to surgery. Post 40, a mammogram is highly advised.

With micromastia there is often a debate as to when and if surgical intervention is appropriate for younger patients. Research (5) has demonstrated significant breast asymmetry can cause adolescent girls and young women to score lower on measurements of mental health, than those with a greater degree of breast evenness.

Doctors at Boston Children’s Hospital assessed 59 girls between the ages of 12 and 21 whose breasts differed by at least one cup size. (6) When compared to a control group of girls without breast asymmetry, the patients were found to have lower self-esteem and worse emotional well-being than their even-breasted counterparts.

One of the study’s authors, Dr. Brian Labow, suggested early intervention, such as consultation, support and surgery if necessary, can help reduce the mental health effects of these conditions.

There are occasionally cases of self-perceived micromastia, which involves a discrepancy between a person’s body image and their internalised images of appropriate or desirable breast size and shape. Patients who demonstrate an obsession with very minor issues could be suffering from mental health conditions such as body dysmorphia.

Whilst procedures are designed to meet what patients think to be desirable and may, in some cases, alleviate psychological suffering, (7) those with more serious mental health conditions may actually worsen rather than improve their illness following surgery.

At MyAesthetics, we believe the more scrupulous, face-to-face time we have with the individual, the better. We always offer and encourage patients to have 2 consultations, prior to surgery with no maximum. Whilst many individuals don’t always need or want a second consultation, this does mean they can take as much time as they need to decide whether or not surgery is for them and we have unlimited opportunities to assess their psychological welfare.

If still unsure about someone’s psychological well-being after follow-up interviews, we believe all potential clients should be referred to a psychiatrist for further evaluation. Psychologists report specialist cognitive behavioural therapy (CBT) is most effective for those with BDD. (8)

CBT works because it focuses on the experience of patients when they are alone (rather than in social situations) and the patient is encouraged to focus on all the characteristics of his or her self to develop a more helpful or flexible view. (9)

Non-surgical alternatives

The sad truth is, that if your breasts are very underdeveloped or there is highly obvious asymmetry, it is unlikely this can be corrected without surgery.

Occasionally patients ask for fillers to be put into the smaller breast and although this would be possible, fillers are only designed for small amounts of volume. If used to augment the breast the results would not only be temporary, but also extremely expensive, as treatment would need to be repeated regularly.

However, one treatment option that can give a more natural result is a fat transfer augmentation. In other words, instead of putting an implant in the smaller breast, you can augment it using your own body fat. This means you’re keeping the breasts natural and you’re still sticking to the principals of keeping them as similar to each other as possible.

If your breasts are a little smaller than you’d like, or only slightly asymmetric there might be some non-surgical interventions you can make. Laser treatments are often recommended by doctors as an effective non-surgical way to enhance the appearance of the breasts. There are some well-known treatments such as the Vampire Breast Lift and Caci bust treatment which are said to lift, tone and strengthen the muscles around the bust area.

You can do various exercises to strengthen your chest muscles and firm up breast tissue. Examples of these are push-ups and dumbbell presses. If you frequently go to the gym, you can try using the butterfly machine as it is designed to tone the chest area.

Even though these exercises can correct poor posture and give your breasts a slight lift, they cannot address damaged tissue or eliminate excess skin like a breast lift does. Chest exercises are a good alternative only if you have decent skin elasticity and want a slight lift.

A well-fitted bra is one the most effective non-invasive ways to instantly lift your breasts. If you have slight asymmetry you can purchase bras with lined cups to even out the difference in size. It is also always best to purchase a bra that will fit the bigger breast comfortably, rather than picking a style more favourable to the smaller size.

Deciding your options

More than ever patients are empowered with choices to achieve the results they want with their appearance. However, it’s important for patients to have realistic expectations when it comes to considering cosmetic procedures. Research the treatment, and read reviews to make sure you pick the right practice for you. It’s imperative not to be swayed by offers or deals. Your surgery should only be performed by fully accredited plastic surgeons who are part of the representative bodies for maintaining excellent industry standards.


  1. Unknown, The Impact of Breast Size on Female Self-Esteem: (USA, Urban Agenda, 2015) https://www.urbanagenda.org/body-confidence/the-impact-of-breast-size-on-female-self-esteem/ [accessed August 24, 2017]
  1. Kirtly Parker Jones, Dr., My Breasts Are Different Sizes – Am I Normal?: (USA, The Scope University of Utah Health Sciences Radio, 2014) https://healthcare.utah.edu/the-scope/health-library/all/2018/05/my-breasts-are-different-sizes-am-i-normal [accessed August 24, 2017]
  1. Boyles, Salynn, Breast Asymmetry Points to Cancer Risk: (USA, WebMD, 2006) https://www.webmd.com/breast-cancer/understanding-breast-cancer-basics [accessed August 24, 2017]
  1. Unknown, Breast cancer incidence (invasive) statistics: (UK, Cancer Research UK, 2014) https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/breast-cancer/incidence-invasive  [accessed August 24, 2017]
  1. American Society of Plastic Surgeons, Study Shows Mental Health Impact of Breast Size Differences in Teens: (USA, American Society of Plastic Surgeons website, 2014) https://www.plasticsurgery.org/news/press-releases/study-shows-mental-health-impact-of-breast-size-differences-in-teens [accessed August 24, 2017]
  1. Nuzzi, Laura C. B.A.; Cerrato, Felecia E. M.P.H.; Webb, Michelle L. P.A.-C.; Faulkner, Heather R. M.D., M.P.H.; Walsh, Erika M. M.D.; DiVasta, Amy D. M.D., M.M.Sc.; Greene, Arin K. M.D., M.M.Sc.; Labow, Brian I. M.D., ‘Psychological Impact of Breast Asymmetry on Adolescents: A Prospective Cohort Study’, Plastic & Reconstructive SurgeryDecember 2014 – Volume 134 – Issue 6, 1116–1123 <http://journals.lww.com/plasreconsurg/Abstract/2014/12000/Psychological_Impact_of_Breast_Asymmetry_on.3.aspx>
  1. Poole, Nigel,‘Consent to Cosmetic Surgery’, (UK, Consulting Room, 2012) https://www.consultingroom.com/blog/cosmetic-surgery-consent [accessed August 24, 2017]
  1. Body Dysmorphic Disorder Foundation, Cognitive Behaviour Therapy, (UK, Body Dysmorphic Foundation website, 2017) http://bddfoundation.org/helping-you/getting-help-in-the-uk/#cognitive-behaviour-therapy [accessed August 24, 2017]
  1. Veale, D, ‘Cognitive-behavioural therapy for body dysmorphic disorder’, Advances in Psychiatric Treatment, 7(2001), 125–132 <http://veale.co.uk/PDf/CBT%20for%20BDD.pdf>