Mastectomy is very safe surgery, and most patients recover well with no complications. As with any surgery, however, there are risks. Possible complications are listed here, but keep in mind that unless stated otherwise, they usually do not happen.

The risks of any surgery are bleeding, infection, and injury to nearby tissues. Some post-operative pain and soreness is expected, but can be effectively treated with pain medication. There will also be a scar on the chest wall. Scarring occurs with all surgery, and is unavoidable.

General anesthesia risks include potential breathing and heart problems, as well possible reactions to medications. For a woman who is otherwise in good health, the risk of a serious complication due to general anesthesia is less than 1%.

The risks related specifically to the removal of the breast include a compromised blood supply to the skin of the chest wall, which may cause loss of some skin. In extreme circumstances, this complication may require a skin graft, but this is very rare. There is also a risk of bleeding into the space where the breast used to be. Sometimes a second operation is required to control bleeding, but this is also uncommon.

There are risks specifically related to removing the nearby lymph nodes (axillary dissection):

• Many patients experience shoulder stiffness after removal of the lymph nodes in the armpit. This stiffness improves over time, especially with exercise and physical therapy.
• A fluid collection, called a seroma, may collect in the armpit. This is relatively common and usually resolves on its own, but may require needle drainage.
• Since the axillary (armpit) lymph nodes normally drain excess fluid from the arm, the removal of these can result in postoperative swelling of the arm on the same side as the breast which is removed. This swelling (called lymphedema) is uncommon, but when it occurs, it can be a persistent problem and carries an increased risk of infection.
• There are some important nerves in the area of the axillary lymph nodes that are at risk during surgery. Many patients will have a numb patch on the inside of the arm after surgery. Nerves to muscles of the back and chest wall are also at risk, but your surgeon will make every effort to protect these nerves during surgery.

There are also risks related to reconstructive surgery. If reconstructive surgery was done using an implant, there is an increased risk of infection. There is also a risk that the scar around the implant will contract.

This can make the breast feel hard, and can be treated by removing the scar tissue or removing /replacing the implant. Each of these involves another surgery. Surgical scars may fade with time, but they will never disappear entirely.

Reconstruction using native tissue from the abdomen, back, or buttocks carries a higher risk of bleeding, and a small chance that the transferred tissue will lose its blood supply and have to be removed.