Gynecomastia

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Gynecomastia facts

  • Gynecomastia is enlargement of the glandular tissue of the male breast.
  • Gynecomastia may occur during infancy and puberty in normally-developing boys.
  • Gynecomastia results from an imbalance in the hormonal environment in the body, with a relative excess of estrogens (female hormones) when compared to androgens (male hormones).
  • Gynecomastia can result as a side effect of numerous medications and drugs of abuse.
  • Gynecomastia is associated with certain medical conditions including hyperthyroidism, chronic kidney failure, and cirrhosis of the liver.
  • Medications and surgical treatments can be used to treat gynecomastia.

What is gynecomastia?

Gynecomastia is enlargement of the gland tissue of the male breast. During infancy, puberty, and in middle-aged to older men, gynecomastia can be common. Gynecomastia must be distinguished from pseudogynecomastia or lipomastia, which refers to the presence of fat deposits in the breast area of obese men. True gynecomastia results from growth of the glandular, or breast tissue, which is present in very small amounts in men. Gynecomastia is the most common reason for medical evaluation of the male breast.

What causes gynecomastia?

Gynecomastia results from an imbalance in hormone levels in which levels of estrogen (female hormones) are increased relative to levels of androgens (male hormones). Gynecomastia that occurs in normally-growing infant and pubertal boys that resolves on its own with time is known as physiologic gynecomastia.

All individuals, whether male or female, possess both female hormones (estrogens) and male hormones (androgens). During puberty, levels of these hormones may fluctuate and rise at different levels, resulting in a temporary state in which estrogen concentration is relatively high. Studies regarding the prevalence of gynecomastia in normal adolescents have yielded widely varying results, with prevalence estimates as low as 4% and as high as 69% of adolescent boys. These differences probably result from variations in what is perceived to be normal and the different ages of boys examined in the studies.

Gynecomastia caused by transient changes in hormone levels with growth usually disappears on its own within six months to two years. Occasionally, gynecomastia that develops in puberty persists beyond two years and is referred to as persistent pubertal gynecomastia.

Picture of male on the left with no gynecomastia and the male on the right with gynecomastia

A number of medical conditions may also result in gynecomastia:

  • Malnutrition and re-feeding (recovery from malnutrition) have both been shown to create a hormonal environment that may lead to gynecomastia. Similarly, cirrhosis of the liver alters normal hormone metabolism and may lead to gynecomastia.
  • Disorders of the male sex organs (testes) can result in decreased testosterone production and relatively high estrogen levels, leading to gynecomastia. These disorders may be genetic, such as Klinefelter's syndrome, or acquired due to trauma, infection, reduced blood flow, or aging. Testicular cancers may also secrete hormones that cause gynecomastia.
  • Other conditions that are associated with an altered hormonal environment in the body and may be associated with gynecomastia are chronic renal failure and hyperthyroidism. Rarely, cancers other than testicular tumors may produce hormones that can cause gynecomastia.

Gynecomastia can also be a side effect of a number of medications. Examples of drugs that can be associated with gynecomastia are listed below:

Medically Reviewed by a Doctor on 9/12/2012

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Gynecomastia - Symptoms Question: What were the symptoms of your gynecomastia?
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Are enlarged breasts in men a medical condition (gynecomastia) or from excess body fat (pseudogynecomastia)?

Enlarged Breast Tissue in Men

Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel, Jr., MD, FACP, FACR

The appearance of enlarged breast tissue in men can be either due to the true enlargement of actual breast tissue or a result of deposition of fat in the pectoral area of the chest. True enlargement of the gland tissue of the breast is due to hormonal fluctuations or imbalances. Breast enlargement in men due to this condition is referred to as gynecomastia. However, especially in obese or overweight men, there can be an increase in fatty tissue over the breast area. This condition, which is not the same as true enlargement of male breast tissue, creates an appearance of enlarged breasts and is known as pseudogynecomastia.

Doctors can usually tell whether or not enlarged breasts in men are due to true gynecomastia by the physical examination, but sometimes other testing is required. True gynecomastia (enlargement of breast tissue), in men is not uncommon and can be seen in normal, healthy boys during pubertyor in men as they age. Medical conditions that interfere with the body's hormonal balance can also cause breast enlargement in men.

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