Causes of a Swollen Male Breast

Men have far less breast tissue than women and consequently have a lower incidence of breast-related ailments. However, men can experience swelling, pain and cancer in their breasts. More common than breast cancer in men is swelling in one or both breasts.

Gynecomastia

Gynecomastia is a condition in males in which the breasts grow abnormally large, taking on a swollen appearance. In fact, the increase in size is related to the growth of breast tissue, rather than fat tissue, according to MedlinePlus, a medical information resource established by the U.S. National Library of Medicine. This condition can affect one or both breasts, and a small lump might be present beneath the nipple. Hormone fluctuations during puberty are often the cause of enlargement of the breasts. Gynecomastia is quite common, as MedlinePlus reports that more than 50 percent of boys develop this condition while in puberty. Gynecomastia might also occur because of the following factors: chemotherapy for cancer treatment and radiotherapy for testicular cancer; exposure to anabolic steroid hormones or estrogen hormones; deficiency in testosterone, the male hormone; kidney failure; use of marijuana; as a side effect of certain medications; and chronic liver disease.

Infection

According to Harvard Health Publications, a breast infection is another way that swollen breasts can occur. Infections often cause swelling because of the infiltration of immune cells to combat the infection. In addition to the recruitment of cells, excess fluid can also build up near the infection site. The infected male might also have a fever and the breast might feel tender.

Cysts

The American Academy of Family Physicians publishes health information on a website called FamilyDoctor.org. In an article on breast problems in men, it notes that one cause of swelling in the breast can be a cyst. A cyst is an enclosed pocket of tissue that is often filled with fluid, but may be filled with other material as well. A large cyst can make the breast swollen and tender. The lump usually feels like a soft grape.

Inflammatory Breast Cancer

Male breast cancer cases account for less than 1 percent of all breast cancer cases, according to the National Cancer Institute. One type of breast cancer that can affect men is inflammatory breast cancer. This signs and symptoms of inflammatory breast cancer include a red, swollen and abnormally warm breast. Cancerous cells that block the lymph vessels in the skin of the breast cause the symptoms.