Here is the link
Gynecomastia is enlargement of the glandular tissue of the male breast.
It is common during infancy, puberty, and in middle-aged to older men. It is enlargement of glandular tissue rather than fatty tissue.
Gynecomastia may occur during infancy and puberty from an imbalance in the hormonal environment in the body
All individuals possess female hormones (estrogen) and male hormones (androgen). 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.
The number of medical conditions may also result in gynecomastia:
Disorders of the male sex organs (testes) can result in decreased testosterone production and relatively high estrogen levels, leading to gynecomastia.
Other conditions that may be associated with gynecomastia are cirrhosis of liver, chronic renal failure and hyperthyroidism.
Side effect of a number of medications like spironolactone (Aldactone), Calcium channel blockers , ACE inhibitor drugs etc
The hormonal preparation taken by bodybuilders has also become a common cause of gynecomastia in young adults.
Symptom of gynecomastia
Enlargement of the male breasts.
It is typically symmetrical in location and may have a rubbery or firm feel.
It usually occurs on both sides but can be unilateral in some cases.
The enlargement may be greater on one side even if both sides are involved.
Tenderness and sensitivity may be present, although there is typically no severe pain.
In most cases, gynecomastia can be diagnosed by a physical examination. In certain cases medical history and tests may be recommended to help establish the cause of gynecomastia such as blood tests to examine liver, kidney, and thyroid function. Measurement of hormone levels in the bloodstream may also be recommended in some cases.
Gynecomastia, especially in pubertal males may go away on its own within about six months.