Unilateral gynecomastia?

[herby]

If gynecomastia is caused by an imbalance to estrogen and androgen then why sometimes only one breast is affected?

[Worrier]

Iam no expert but one side of the breast can be more easier stimulated by hormones in some people.If you have a hormone problem or are going through puberty.
Also sometimes you can uneven fat deposits when you gain weight which put more fat on one side although this is rare.
I have unilateral gyne caused by a medication I used to take, my hormones were fine. Apparently unilateral gyne is a rare effect from using all kinds of medications. Sometimes it regresses, sometimes it doesn't when the med is stopped.

[DrBermant]

If gynecomastia is caused by an imbalance to estrogen and androgen then why sometimes only one breast is affected?

Uneven and Unilateral (one sided) gynecomastia can happen. Breasts of women also are unven.  The factors contributing to the uneven condition are just not known.  However, asymmetry is normal for the human body.

A little bit of gland on one side can be stimulated to grow.  I saw one case where one bodybuilder had a crater deformity on one side where he had gynecomastia removed by another doctor leaving nothing between the skin and the muscle.  It looked terrible, however did not grow when stimulated.  The other side had not grown before during prior stimulation and had not been operated on.  That second side was blown up and tender from bodybuilding steroids.  This points to variations that can be due to amount of tissue present and degree of stimulation.

I have discussed this condition with many endocrinologists.  The consensus is that gynecomastia is a complex process that currently is just beyond our complete understanding.

Hope this helps,

Michael Bermant, MD
Learn More About Gynecomastia and Chest Sculpture

[Paa_Paw]

The old Comic, Bob Hope once defined 'Virus' as a medical word meaning "your guess is as good as mine"  or "I dunno."

Since viruses are now better understood, perhaps we need to add a new term to our vocabulary.