Gynecomastia (American English) or gynaecomastia (British
English) is the development of abnormally large breasts on men.
The term comes from the Greek gyne meaning "woman" and mastos
meaning "breast". The condition can occur physiologically in
neonates, in adolescents, and in the elderly. In adolescent boys
the condition is often a source of distress, but for the large
majority of boys whose pubertal gynecomastia is not due to
obesity, the breast development shrinks or disappears within a
couple of years. The causes of common gynecomastia remain
uncertain, although it has generally been attributed to an
imbalance of sex hormones or the tissue responsiveness to them,
A root cause is rarely determined for individual cases. Breast
prominence can result from hypertrophy of either breast tissue
or pectoral adipose tissue, and often a combination of the two.
Breast prominence due solely to excessive adipose is often
termed pseudogynecomastia. Potential pathologic causes of
gynecomastia are: medications including h