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Schedule A ConsultationGynecomastia typically affects both sides of the chest, but in some cases, men develop breast tissue on only one side. This condition, known as unilateral gynecomastia, can lead to asymmetry, discomfort, and increased concern due to its uneven appearance. Whether the change is sudden or has developed gradually, understanding what causes unilateral gynecomastia and how to treat it can bring much-needed clarity.
This article covers the causes, symptoms, and treatment options for men with gynecomastia on one side of the chest.
Unilateral gynecomastia refers to the enlargement of glandular breast tissue in one breast, typically behind or beneath the nipple. It may present as:
This condition is more than just fat—it involves actual glandular growth triggered by hormonal imbalance or other underlying causes.
Hormonal Imbalance
A temporary or ongoing imbalance between testosterone and estrogen can cause one-sided breast tissue growth. This often happens during puberty but can also occur in adulthood.
Medication Side Effects
Certain medications may affect only one side depending on tissue sensitivity. Common offenders include anti-androgens, antidepressants, heart medications, and steroids.
Steroid or Supplement Use
Anabolic steroid use or testosterone boosters can disrupt hormone levels and may lead to gynecomastia, sometimes more prominently on one side.
Underlying Health Conditions
Kidney or liver disease, tumors (such as testicular or adrenal), or thyroid disorders can contribute to hormone shifts that trigger unilateral breast development.
Idiopathic (No Known Cause)
In many cases, especially in teens and young adults, there may be no clear cause. The tissue may develop spontaneously and persist unless surgically removed.
Before diagnosing unilateral gynecomastia, it’s important to rule out other conditions, including:
Any persistent, firm lump under one nipple should be evaluated by a specialist.
An accurate diagnosis usually involves:
At our Newport Beach clinic, we specialize in male chest evaluation and can help you determine the exact cause of your symptoms.
Mild cases that develop during puberty often resolve on their own within 6 to 24 months. However, persistent or adult-onset unilateral gynecomastia typically requires surgical correction.
The procedure includes:
Surgery is performed as an outpatient procedure and takes about 1 to 2 hours. Most men return to work within 3 to 5 days.
If you’ve noticed one side of your chest is larger, firmer, or more sensitive than the other, you may have unilateral gynecomastia. Dr. Joseph Cruise is a leading expert in male breast surgery and can help determine whether surgery is right for you. We offer private, judgment-free consultations and personalized treatment plans for all types of gynecomastia.
Schedule a gynecomastia consultation today to get the answers you need and take the first step toward a balanced, confident chest.
Dr. Joseph Cruise is a board-certified plastic surgeon with over 20 years of experience. Regarded as one of the top gynecomastia surgeons in the world, Dr. Cruise has gynecomastia-specific content that can be found at lagynecomastia.org. Dr. Cruise has dedicated his career to cosmetic surgery but has also had extensive training in General Surgery, Hand Surgery, and Microvascular Surgery. Dr. Joseph Cruise is also a member of the Rhinoplasty Society as well as the American Society of Plastic Surgeons.
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