I know that some women have arm swelling and pain after breast cancer surgery. Why does it happen?

Pain happens after. most surgical procedures. In mastectomy, a nerve that exits the side of the breast is usually injured or sacrificed and irritation of is causes pain or noxious tingling especially when the arms swing during walking. Swelling is independent of that and can be caused by removal of lymph nodes and exacerbated by not putting the limb thru frequent adequate range of motion- usually out of fear of pain.
Lymphedema. Arm swelling after breast cancer surgery used to be an all-too-common occurrence secondary to the removal of many of the lymph nodes under the armpit . The incidence of lymphedema increases in response to radiation therapy that encompasses this area.Modern techniques for lymph node evaluation (sentinel lymph node biopsy) remove far fewer lymph nodes, dramatically reducing the risk of lymphedema.
Lymphedema. If a person has had surgery in the axilla to check for lymph nodes, they can be at risk for lymphedema or arm swelling. This surgery disrupts the passage way for fluid to drain from the arm which then causes swelling. Thankfully, lymphedema from breast surgery is not a profound as it once was since less lymph nodes are removed.
Lymph nodes. Doing breast cancer surgery the lymph nodes are removed. This causes the lymphatic fluid to back up in the arm.

Related Questions

I know that some women have arm swelling after breast cancer surgery. Why?

Lymphedema. The arm swelling you are describing occurs secondary to disruption of the lymphatic circulation draining the arm, either via lymph node removal and/or radiation therapy. When we used to remove 10-20 lymph nodes, the lifetime incidence was ~25%. Nowadays, with sentinel lymph node biopsy alone, the risk is closer to 5%. Hopefully, in the future we won't have to remove any lymph nodes. Read more...
Lymph edema. Lymph is the fluid in tissues. After surgical procedure some people have a tendency to develop swelling because lymph nodes are removed - the collection system for lymph. Emotionally deep skin is the layer we bury sadness - literally we are weeping inside. It is easier to bury emotions makes this bearable. Read my book called meridian medicine available on itunes to learn more. Read more...

My mom used to have breast cancer few years ago she had surgery, chemo, radio, and now hormonal. She is now feeling itchy INSIDE her arm and swelling?

CA vs lymphedema. Likely lymphedema. Could be breast cancer recurrence. See oncologist for imaging and physical examination. If lymphedema see a lymphedema specialist. Read more...
Could be lymphedema. Is this the arm on the side of the surgery and radiation? Were the lymph nodes removed? Swelling of the arm (lymphedema) can occur years after treatment and can be managed with physical therapy and a sleeve. However, a recurrence of the cancer in the axilla (under the arm) should be ruled out in any patient who develops lymphedema years after treatment. Read more...