From the Guidelines
Gynecomastia is primarily caused by an imbalance between estrogen and testosterone levels in males, resulting in enlarged breast tissue, with common causes including puberty, aging, obesity, and certain medications, as well as health conditions and substance use, as noted in 1. The condition can be physiological, occurring in neonates, adolescents, and with aging, or it can be pathological, resulting from various factors such as hormonal changes, medication side effects, and chronic diseases like liver disease 1. Some key factors to consider in the development of gynecomastia include:
- Hormonal imbalance: An excess of estrogen relative to testosterone can lead to gynecomastia.
- Medications: Certain drugs, including antipsychotics, antidepressants, anabolic steroids, anti-androgens, and some heart medications, can cause gynecomastia as a side effect.
- Health conditions: Liver or kidney disease, hypogonadism, hyperthyroidism, and tumors can contribute to the development of gynecomastia.
- Substance use: Alcohol, marijuana, heroin, and amphetamines have been associated with gynecomastia. It's also important to note that gynecomastia can sometimes be a marker for underlying endocrine disorders, as mentioned in 1. In many cases, particularly during puberty, gynecomastia may resolve on its own within six months to two years, but if it persists, treatment may involve addressing the underlying cause, lifestyle changes, or medical interventions such as tamoxifen or surgery for tissue removal, as suggested by the general approach to similar conditions 1. Given the potential for gynecomastia to be associated with serious underlying conditions, consulting a healthcare provider is crucial for determining the cause and appropriate treatment, especially if breast enlargement is noticed.
From the FDA Drug Label
5.4 Gynecomastia Spironolactone can cause gynecomastia. In a Randomized Spironolactone Evaluation Study, patients with heart failure treated with a mean dose of 26 mg of spironolactone once daily, about 9% of the male subjects developed gynecomastia. The risk of gynecomastia increases in a dose-dependent manner with an onset that varies widely from 1 to 2 months to over a year. Gynecomastia is usually reversible.
Gynecomastia can be caused by spironolactone. The risk of developing gynecomastia increases with the dose of spironolactone and can occur anywhere from 1 to 2 months to over a year after starting treatment. According to the study, about 9% of male subjects developed gynecomastia when treated with a mean dose of 26 mg of spironolactone once daily 2.
From the Research
Causes of Gynecomastia
- Gynecomastia is caused by an imbalance in hormonal physiology, with an increase in estrogen action relative to androgen action at the breast tissue level 3, 4
- The condition can be physiological, occurring in newborns, adolescents, and older men, or it can be caused by underlying medical conditions, such as endocrine disorders, liver failure, or chronic kidney disease 5
- Certain medications can also cause gynecomastia, including:
- Spironolactone, cimetidine, ketoconazole, hGH, estrogens, hCG, anti-androgens, GnRH analogs, and 5-α reductase inhibitors, which have a definite association with gynecomastia 6
- Risperidone, verapamil, nifedipine, omeprazole, alkylating agents, HIV medications (efavirenz), anabolic steroids, alcohol, and opioids, which have a probable association with gynecomastia 6
- Gynecomastia can also be caused by non-endocrine illnesses, such as liver failure and chronic kidney disease 5
Types of Gynecomastia
- Physiological gynecomastia: occurs in almost 25% of cases, is benign, and self-limited 5
- Pathological gynecomastia: caused by underlying medical conditions or medications 3, 4, 6, 7, 5
- Acute gynecomastia syndrome: characterized by a single painful/tender breast (mastodynia) associated with breast enlargement, and is often transient and resolves spontaneously over time 7