Breast health: Should you be worried if one breast is different to the other?

It's one of the most common but least talked about concerns among women: "One of my breasts is slightly different in shape or size, is that normal?" According to leading breast surgeon and breast cancer researcher Associate Professor Sanjay Warrier, the answer is yes, most of the time.
 

"Very few women have perfectly symmetrical breasts," Associate Professor Warrier said.
 

"Minor differences in shape, size or position are incredibly common and in most cases completely harmless. Our bodies are not perfectly symmetrical and breasts are no exception."
 

But what about when the difference is new, or becomes more noticeable over time?
 

"That's when we start to pay closer attention," he said.
 

Associate Professor Warrier is one of the world's leading breast health and breast cancer surgeons who has built a highly respected practice in Sydney. The practice spans three locations with its main surgical centre located at the Chris O'Brien Lifehouse in Camperdown, and the other sites at BMA House, Macquarie Street, Sydney and Bondi Junction Medical, Oxford Street, Bondi Junction.
 

In addition to Associate Professor Warrier's breast health and surgical work, he also dedicates considerable time to research exploring and developing advancements in breast cancer detection and treatments to improve outcomes for patients. He also codeveloped Australasia's first Master of Advanced Surgery (Breast Surgery) which is delivered through the University of Sydney.
 

Breast change is normal throughout a woman's life
 

"A woman's breasts can naturally change in shape, size and density due to hormonal fluctuations throughout her life. During puberty, rising estrogen causes breast development. In pregnancy, breasts often enlarge and become more tender due to increased blood flow and milk duct growth," Associate Professor Warrier said.
 

"After breastfeeding, they may lose volume or appear softer. Menstrual cycles can cause temporary swelling or tenderness. In menopause, declining estrogen levels lead to reduced glandular tissue and increased fatty tissue, often making breasts feel softer or less full.
 

"These changes are common and usually not a cause for concern unless accompanied by other unusual symptoms."

What changes might signal a concern
 

Asymmetry itself isn't usually a red flag. What matters is when the asymmetry is new, has changed rapidly, or is accompanied by other symptoms.
 

"If one breast becomes visibly larger, firmer, swollen or the nipple inverts or changes direction, particularly over a short period of time, it could be a sign of something more serious, like an underlying tumour or inflammatory breast cancer," he said.
 

Other concerning symptoms may include dimpling, thickening of the skin, a persistent lump, unusual discharge or changes that persist throughout your cycle.
 

"If you notice any new or progressive change, especially if it's isolated to one breast, you should get it checked immediately," Associate Professor Warrier said.
 

Know your normal and trust your instinct
 

Associate Professor Warrier is urges women to become familiar with their own breast shape and feel so that subtle changes are easier to spot.
 

"You are your own best advocate. Knowing what's normal for you is the first step to recognising when something isn't," he said.
 

Regular self-examinations, especially in the shower or lying flat, can help you understand your body and give you confidence in spotting changes early.
 

Not all lumps are cancer but they do need checking
 

Many women avoid seeing their doctor for fear of bad news. However Associate Professor Warrier stressed that most breast changes are not cancer.
 

"Benign conditions like cysts, fibroadenomas or hormonal fluctuations are common and harmless, but we never take chances," he said.
 

"The good news is, early detection of breast cancer dramatically improves outcomes and most changes turn out to be benign. However, the only way to know for sure is to get assessed by a professional.
 

"Book an appointment to visit my clinic or see your GP."
 

Your risk isn't about symmetry it's about your profile
 

While asymmetry itself isn't a risk factor, Associate Professor Warrier encourages all women to understand their individual risk profile which includes factors like family history, age, breast density, hormonal exposure and lifestyle.
 

"There's no one-size-fits-all answer in breast health," he said.
 

"It's about personal awareness, preventative screening and not ignoring your intuition."

More information on breast cancer detection and screening is available at www.drsanjaywarrier.com.au.
 

About Associate Professor Sanjay Warrier
 

Associate Professor Sanjay Warrier is a past President and current committee member of Breast Surgeons of Australia and New Zealand (BreastSurgANZ). His views are those of his own, not BreastSurgANZ. Associate Professor Warrier's surgery is located at the Chris O'Brien Lifehouse and he also has clinics at Oxford Street, Bondi Junction and Macquarie Street, Sydney. He is published in numerous peer-reviewed journals and won the Royal Prince Alfred Hospital's Patron's Prize for best scientific research.