Male breast enlargement, or gynecomastia, often stems from a combination of genetics and weight gain. While hormonal imbalances—such as an increase in estrogen or a decrease in testosterone—can contribute, most cases persist even after hormone levels are corrected.

That’s because the excess fat and glandular tissue do not disappear with hormonal therapy or weight loss alone. Surgery becomes the most effective option to remove these stubborn deposits and restore a flatter, firmer chest.

Gynecomastia can affect one or both breasts, sometimes unevenly. Some men notice swelling or tenderness in the chest, which may prompt them to seek treatment. Others are more concerned with the cosmetic impact, especially when wearing fitted clothing or going shirtless at the beach or gym.

In addition to genetics, weight gain, and hormonal issues, certain medications, substances, and health conditions can also contribute to gynecomastia. These may include:

• Anti-androgens used to treat prostate conditions

• Anabolic steroids

• Certain antidepressants or anti-anxiety medications

• Liver or kidney disease

• Marijuana or THC use (PubMed)

Addressing underlying medical issues is important, but it often does not reverse the physical changes already present in the chest.