More Resources Why Is My Right Boob Bigger Than My Left?

Why Is My Right Boob Bigger Than My Left?

Most women have probably asked themselves at some point, "hey, why is my right boob bigger than my left?" While it may seem like an odd question to some, breast asymmetry is quite common, and something a lot of women can encounter at some point in their lives. That being the case it is important to understand the potential causes behind it.

We completely understand why for some women noticing a difference between their breasts will spark fears about 'the c-word', and sadly breast cancer can cause such differences. However, we hope when you're done reading this comprehensive guide, you'll see that it's not the only cause, and that - especially if you're a breastfeeding mom - one boob being bigger than the other is usually down to something less serious and more easily dealt with.

In this article the Limerick team will explore the phenomenon of breast asymmetry, with a focus on breast engorgement as a potential cause. We'll discuss the signs, causes, and treatments of breast engorgement, as well as whether it's something you should be concerned about. So, let's delve into the mysterious world of uneven breasts and find the answers you're seeking.

Questions moms ask: "Why is my right boob bigger than my left?"

What is breast engorgement?

Before we address the question of "Why is my right boob bigger than my left?", and why the answer may be breast engorgement, it's important to understand just what engorgement is. Breast engorgement refers to the swelling and increased firmness of the breast tissue due to an accumulation of breastmilk and/or other fluids. This condition can cause discomfort, pain, and tenderness in the affected breast, and while engorgement can occur in either breast, it's not uncommon for one to be more affected (or more susceptible) than the other.

Questions moms ask: "Why is my right boob bigger than my left?"

Signs of breast engorgement

Before you can seek appropriate treatment and relief for breast engorgement, you need to be able to identify the signs and symptoms that typically identify the condition. Common symptoms of breast engorgement can include:

  • Swollen, firm, and tender breasts
  • Breast skin appearing shiny and tight
  • Warmth or heat in the affected breast
  • A temporary flattening of the nipple
  • Mild to moderate pain or discomfort

If you notice these signs and wonder, "why is my right boob bigger than my left?", breast engorgement could well be the culprit.

Questions moms ask: "Why is my right boob bigger than my left?"

What causes breast engorgement?

There are several factors that can contribute to breast engorgement. Some of the most common reasons for breast engorgement include:

Insufficient breastfeeding or pumping

When a breastfeeding mother doesn't express often enough, either through nursing or pumping, milk can be retained in her breasts. This can lead to leaking, or to engorgement. Don't forget that babies can have a preference for one breast over the other and that there are other factors that may lead to one breast expressing more than the other, and in turn make engorgement more likely on the opposite side.

Blocked milk ducts

Milk ducts transport milk from the mammary glands to the nipple. If a milk duct becomes obstructed or blocked, milk may accumulate in the breast, causing engorgement and unevenness.


Infections, (and in particular Mastitis), can cause inflammation and swelling, leading to breast engorgement. When Mastitis or another infection is responsible for breast engorgement it will typically be accompanied by pain, redness, and fever.

Hormonal fluctuations

Hormones can play a significant role in breast tissue changes, and fluctuations in hormone levels can result in engorgement. This is particularly common during pregnancy and postpartum, when estrogen and progesterone levels can cause breast tissue to swell and retain fluid.

Questions moms ask: "Why is my right boob bigger than my left?"

Other things to bear in mind

Natural Asymmetry

The human body is not perfectly symmetrical. Your breasts may not be mirror images of each other, exactly the same - but they're not supposed to be, and in some cases there will be a noticeable difference between the two. Some women will have known this and dealt with it since puberty, others won't, but the important thing is to recognise what is 'normal for you', be aware of anything new, any changes to that normal, and see an appropriate medical professional if those changes are causing you concern.

If you've had surgical breast augmentation, reduction or other cosmetic surgeries

In addition to the purely biological causes of breast asymmetry that we're talking about in this blog, if you've had any cosmetic (or other) surgery performed on your breasts then it's worth investigating whether or not something related to the surgery could be behind your asymmetry, and again, consult with an appropriate healthcare professional if you think this might be the case.

Questions moms ask: "Why is my right boob bigger than my left?"

How can breast engorgement be treated?

If you've determined that breast engorgement is the reason why one breast is currently larger than the other, what can you do to alleviate discomfort and prevent complications?The Limerick team know that effective treatments for breast engorgement can include:

Frequent breastfeeding or pumping: Ensuring that you express milk regularly, via either pumping or feeding, can help prevent milk being retained by the breasts and alleviate engorgement.

Warm compresses: Applying a warm cloth or a heating pad to the affected breast can encourage milk flow and reduce swelling.

Cold compresses: Likewise, engorgement can be treated via the application of cold packs. The application of cold packs, cloths or items can help decrease any inflammation of the breast and provide relief from pain and discomfort associated with engorgement.

Massage: Gently massaging the breast in a circular motion can help stimulate milk flow, which can, in turn, alleviate engorgement.

Over-the-counter pain relievers: If you wish then you can also take Nonsteroidal anti-inflammatory medications (NSAIDs) to help reduce the pain and inflammation associated with breast engorgement.

Questions moms ask: "Why is my right boob bigger than my left?"

Do I need to worry about breast engorgement?

In the opinion of the Limerick team, breast engorgement is usually the most likely answer to the question, "why is my right boob bigger than my left?". It can be uncomfortable and even painful, but breast engorgement is typically a temporary condition that is nothing to worry about, and which can easily be managed with proper care and treatment. In most cases the important thing is related to the information that we've presented in this guide - knowing what to look for, why it might be happening, and what you can do about it - however, if you're concerned about your breast asymmetry or if your symptoms worsen or persist, you should consult an appropriate healthcare professional to rule out other potential causes and receive appropriate guidance.

Questions moms ask: "Why is my right boob bigger than my left?"

More practical breastfeeding support

In addition to "Why is my right boob bigger than my left?" other questions answered in our 'questions moms ask' series of articles that can be found in our resource center include "why does the Haakaa hurt?", "why do my nipples turn purple sometimes?" and many more besides. Alternatively, if you're looking to learn more specifically about breast engorgement, check out the articles here and here.