Gynecomastia, informally called “gyno,” is the benign enlargement of male breast tissue resulting from the proliferation of glandular material, not fat accumulation. It is a common condition that can affect males at any age, with estimates suggesting over 50% of men may experience it. The underlying mechanism involves a disruption in the hormonal balance, specifically an increased ratio of estrogen to testosterone. While typically harmless physically, this enlargement often causes significant psychological distress.
Recognizing the Defining Physical Characteristics
The most telling sign of true gynecomastia is a firm, distinct mass located directly beneath the nipple and areola complex. When palpating the area, this glandular tissue feels rubbery, disc-shaped, and is usually mobile under the skin. The size of this mass varies widely, but its localized, concentric position around the nipple is characteristic.
Tenderness or sensitivity is another common symptom, particularly during the early stages of development or in adolescents. This discomfort may manifest as mild pain when the area is touched or when clothing rubs against the nipple.
Differentiating Between True Glandular Tissue and Fat
Distinguishing true gynecomastia from pseudogynecomastia (excess fat deposition without glandular growth) is important. The “pinch test” is often used to differentiate the two conditions. True glandular tissue feels dense, firm, and localized in a small, distinct, rubbery disc immediately under the areola.
If the enlargement is due only to excess fat, the tissue will feel soft, squashy, and diffuse, spreading evenly across the chest. Pseudogynecomastia is strongly associated with obesity and often resolves with generalized weight loss, while the firm glandular tissue of true gynecomastia does not shrink with diet and exercise alone.
Common Hormonal and Medical Causes
Glandular growth is almost always caused by a hormonal imbalance favoring estrogen action over testosterone at the breast tissue level. Estrogen stimulates glandular tissue growth, and proliferation occurs when its relative level is too high. The condition naturally peaks at three common life stages: newborns (due to maternal estrogen exposure), adolescent boys during puberty, and men over the age of 50.
In older men, a natural decline in testosterone combined with increased body fat shifts this balance, as body fat contains the aromatase enzyme that converts androgens into estrogens. Certain medications are also well-documented causes, including anabolic steroids, anti-androgens for prostate conditions, specific psychiatric drugs, and heart medications like digoxin and calcium channel blockers. Underlying health problems, such as chronic liver disease, kidney failure, and hyperthyroidism, can also disrupt hormone metabolism and clearance.
When to Seek Medical Consultation
While most cases are benign, certain signs warrant prompt medical evaluation to rule out serious underlying issues. Any rapid, recent enlargement of the breast tissue should be checked by a doctor, especially if the growth is unilateral, affecting only one side of the chest. Persistent or severe pain and tenderness lasting more than a few weeks should also be investigated.
Urgent red flags include any nipple discharge, particularly if bloody, or the presence of skin changes like ulceration, dimpling, or nipple retraction. A medical professional can perform a physical examination and order tests to confirm the nature of the lump and check for hormonal or systemic causes.